Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Let’s Challenge SPIDER

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In the very interesting thread http://www.planningplanet.com/forum/forum_post.asp?fid=1&Cat=9&Top=64826 I wrote that Spider Project software can calculate project schedules and budgets taking into account all possible constraints and has all functionality necessary for proper planning.
I proposed to suggest hard tasks, something that most or all packages cannot do. I will answer if and how it can be done in Spider.
For those who did not hear about Spider Project - this is Russian professional PM software. At the moment it is used in 26 countries.

So this thread is for questions on functionality that is useful but is not supported by the packages that you use.
Rafael Davila hopes that other software developers will look at this discussion and then will make their packages more functional.

I will start with answering to his question on project scheduling with financial constraints.

Sometimes when you start the project you have not all necessary money. You may know when and how much money will come to the peoject (financing schedule). If financing schedule is a part of your project schedule model then Spider Project will calculate project schedule taking into account financial limitations and delaying activities when there are no money to proceed.
Actually it is even more complex - some activities may generate money (selling flats in the building in the process of construction for an example), that may be used for financing other activities.

All this can be simulated and an example of the project with financial constraints is included in the Spider Demo.

I am waiting for your questions and hope for fruitful discussion on PM software functionality.

Best Regards,
Vladimir

Replies

Safwan,

it depends on how initial model was created.

If at the planning stage it was not assumed that Subcontractor 2 may replace Subcontractor 1 at point C, it will be necessary to replace resource assignments.

If such possibility was considered then it makes sense to assign Skills that include resources of both Subcontractor 1 and Subcontractor 2 and give resources of Subcontractor 1 higher priority. If Subcontractor 2 will be selected for doing this job it is sufficient to change resource priorities.

One more solution is creating conditional network. Spider Project has special activities that have zero duration and two states Yes or No. This activity precedes to two network branches. If condition of Switch is Yes one branch will be selected (and other ignored), if No then another. States of the Switch activity may be selected manually or basing on some user defined rule.

In your case it is reasonable to create Switch activity that precedes to start of point C execution and create two branches – one if the job will be done by Subcontractor 1 and second if point C will be done by Subcontractor 2. These branches may include different activities. Then you may set the rule like If the forecast of completing point B by Subcontractor 1 is later than certain date Switch will automatically select the state that means that point C will be done by Subcontractor 2.

It looks like using Switch activity is the best method in your case.

Safwan H.
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"Defining project resources specify if they belong to special subcontractors or can be used by many of them. Spider Project will optimize project schedule taking this into account."

Expanding on my question;
Subcontractor 1 has been scoped with A, B and C, Subcontractor 2 with D, E, F.
Consider both have 'special resources' assigned to these activities/scope, and initially all is ok. At some point 'B' is delayed which opens up an opportunity for Subcontractor 2 to complete 'C' as well his scoped 'D, E, F' without affecting himself.

Would Spider maintain levelling with 'special subcontractor resource' or consider breaking this if the opportunity arises as per the above example?

"In this case Spider Project will select who will do the work basing on resource availability, user defined priorities and user defined criteria"

Or is my answer in the above quote and I'm just missing it..

Defining project resources specify if they belong to special subcontractors or can be used by many of them. Spider Project will optimize project schedule taking this into account.

Another case: when subcontractors use the same resource but it does not make sense to move it from one subcontractor to another until certain work was done (due to the distance or other reasons). This is modeled using spatial resources. In particular case when two or more subcontractors work in the one place they can share common space and resource will be used by all of them in the optimized schedule.

Skill means that resources belonging ti Skill can do the same work though with different productivity. You may create skill that includes resources of different subcontractors. In this case Spider Project will select who will do the work basing on resource availability, user defined priorities and user defined criteria (minimal cost, largest productivity or something else).

Let me know if your question was answered.

Safwan H.
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Apologies if reviving this thread upsets a few people but I figured it's the best place to ask.

I don't know too much about Spider other than postings from Rafael and Vladimir - bear this in mind when reading the question below.

I take it that Spider can resource level based on the selected scope a subcontractor is given throughout a project and can adhere to this rule throughout the project if modelled so. Can Spider show some optimization by the use of transferring resource from one subcontractor resource to another? (I understand that some will say humans should do this, but I'm curious if Spider could flag this)

I'm guessing the answer may be in skills (?)

George,

I tried those sample projects earlier. Spider Project j301_1 instance default duration is 43 days (optimal).

I will look at your method and we will discuss this matter further (not in this forum). There are certain requirements to any algorithms that we use for project, program, portfolio scheduling. These requirements include:

- Multiple dependencies between the same activities that link any point of preceding activity with any point of succeding activity with lags that can be positive and negative and measured in time of quantity units,

- Resources, activities, lags may have own unique calendars,

- If skills are assigned the scheduling engine shall select and assign the resources that have necessary skills basing on their availabilities and user defined criteria,

- Activity durations may be calculated basing on quantities of work to be done and assigned resource productivities, if skills were assigned the duration is not known before project scheduling,

- Resource assignments may be partial and variable (when resource workloads or quantities may change during activity execution),

- Not only renewable but also consumable resources shall be considered,

- Project financing shall be considered as one of many schedule constraints,

- Etc. (there are many other requirements that need to be followed).

Sample projects in both production and project sets are too simple in structure though hard for finding optimal solution. The scheduling algorithm shall take into consideration all possible constraints and conditions.

Production scheduling may have different requirements like taking into account set-up durations.

In any case a lot of work is ahead to make an algorithm practical.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

First, I must apologize for my misunderstanding of your answer. I do not have a deep knowledge of project scheduling, and mainly, I do not know how professional PM software like Spider works. By now I think I understand your answer. Anyway, thanks for your detailed response to my question.

For a change, I have one resource-constrained project scheduling benchmark problem for Spider. I took it from the PROJECT SCHEDULING PROBLEM LIBRARY (http://129.187.106.231/psplib/). It is the j301_1 instance with the optimal makespan 43. It is small (30 activities) and not too complex (single mode). You can download the j301_1 pdf file from http://www.4shared.com/document/zSX59zRv/j301_1_project_sched_benchmark.html

Vladimir, can you take a look at my software. I developed an optimization method called sweep algorithm. The method is based on discrete event simulation, and it can solve resource-constrained project scheduling problems. I tested the method by developing software, called Sweeper, and solving the job shop scheduling benchmarks with very good results. Sweeper can match the Spider’s results within 1-2 seconds, and as its calculation continues, it finds shorter and shorter schedules.

You can evaluate the method and software, and if you like it we can develop software, based on the method, which would solve your real-world project scheduling problems. Such software can be included in Spider. It would be a good complement to Spider’s other optimization software. As Rafael said (6-13-2011): “If there are other algorithms that should be added because they are better under certain circumstances, why not adding these options. I have no problem with having many algorithm options, prioritization is what confuses me.”

You can download a read_me text file from http://www.4shared.com/document/A5fBzFKS/read_me_Sweeper_exe.html

The read_me file has instructions for downloading, installing, and running Sweeper.exe. It also has links to my conference papers about the method and benchmark testing.

You can download a white paper about the method from http://www.4shared.com/document/mlba3MpK/Sweeper_explained.html

 

Rafael,

Can you take a look at Sweeper also? I am interested in your thoughts. Perhaps, you will even revamp Sweeper to your specs as local mechanics in San Juan fixed the Obama’s vehicle.

Best Regards,

George

Thank you, George.

Yes, I have read your post and answered.

Spider Project shall produce certain schedules with the same sets of initial data and the same methods chosen. It is project management requirement. If the Contractor submits some schedule to the Client both shall be sure that if anybody will run the scheduling again the result will be the same. So we could not afford anything uncertain (like time of the scheduling and the number of iterations). There are other reasons like the need for project trend analysis.

So we can create additional steps for resource constrained scheduling (now there are Standard, Advanced, Optimization, Optimization Plus levels) but cannot afford any uncertainty in the way the schedule is calculated. We already slightly improved Optimization Plus in yesterday release.

And as I wrote earlier the sample projects in the set were specially created to be hard and they are especially hard for Spider because our approach to iterative improvement uses WBS, the points where paths are merged. Your examples remind the portfolio scheduling but for this task optimization does not mean the shortest duration.

For really large projects with complex resource assignments (skills, partial assignments, conditions on continious work, resource production and consumption, etc.) Spider scheduling may take hours. So algorithms that find the best result for the benchmark schedules taking minutes of calculation could not be used at all in the real life.

I will try other samples later or will ask somebody in our office to do it. For me it is not easy to find the time for entering data.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

As I said before (6-15-2011): For optimum (or the best found) makespans/schedules of the benchmarks, see for example my conference paper

http://www.informs-sim.org/wsc08papers/088.pdf, Table 1 and 2, column OPT.

The optimum or the best found makespan/schedule for ABZ7 is 656 (time units).

Spider schedule: 756 days, +15% (756x100/656 - 100).

P6 Default schedule: 1071 days, +63%.

P6 Best schedule (Late start): 797 days, +21%.

Vladimir, did you read my post from 6-14-2011? In the part for you, I suggested to allow the users to select calculation time for Spider. Rafael is willing to wait for a Spider schedule up to an hour. What do you think of the suggestion? Is it practical or useful?

Can you try ABZ8 and ABZ9? They are as difficult as ABZ7.

Best Regards,

George

George,

I did not find the optimal duration for abz7.

Spider schedule lasts 12 hours and 36 minutes:

Photobucket

The schedules created by Spider shall be stable. If somebody will calculate project schedule with the same initial data and the same options the results shall be the same also. Don't forget that the schedules may live several years and recalculated at least each week. That is why we cannot afford anything random. But our testing was very useful and we will strengthen Optimization Plus option. As I wrote earlier the samples are not usual for projects and Spider did not use its full potential for schedule optimization but they were still very useful and showed some ways for future improvements.

I transfered minutes to days and calculated the schedule both in Spider and P6.

Spider schedule: 756 days,

P6 Default schedule: 1071 days,

P6 Best schedule (Late start): 797 days,

Optimal schedule: ???

Best Regards,

Vladimir

Rafael Davila
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George,

Again calculations at the blink of the eye. Not all of our jobs are made up of thousands of activities. My jobs are usually around 600 activities.

Our scenarios usually are such that a single dominant chain makes up the critical path and the other parallel chains do have enough float as to even allow us to reduce the availability of resources as to reduce idle time, then as there is progress the job starts to lag we increase the availability of resources up to a practical limit, here the resource leveling algorithm becomes very relevant. In our jobs parallel process that share many resources usually have the same resource demand sequence such as it would be the case of 10 independent buildings on a housing complex, we usually offset them in a way resources move smoothly on a controlled way.

Our job are different but some improvement will always be welcomed.

You can download la16 from the following link.

http://www.mediafire.com/?ottbgt5q7gqxv99

Got la16 with a duration of 17.21 hrs (17:13) or 9% (17.21/15.75-1) over best known solution by applying individual activity priorities.

Photobucket

Best regards,

Rafael

George Mejtsky
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Rafael,

I love the Obama’s revamped vehicle. But that gold inside is a bit too much, right?

How long did Spider calculate the schedules? Is it again “The calculation time is always at a blink of the eye, as soon as resource leveling icon is clicked” as you said?

The optimum makespan for LA01 is 666. So Spider’s 715 (11.55 hours, 11x60+55=715) is +7%, or 690 (11.30 hours, 11x60+30=690) is +4%.

The optimum makespan for LA16 is 945. So Spider’s 1047 (17 hours 27 minutes, 17x60+27=1047) is +11%.

For optimum (or the best found) makespans of the benchmarks, see for example

http://www.informs-sim.org/wsc08papers/088.pdf, Table 1 and 2, column OPT.

There is enough space for improvement in the schedules for these very small and easy problems. Perhaps, the calculation time of several more blinks of the eye will do it.

Rafael, did you notice that as the problem size (number of activities) grows, the difference between Spider’s schedule and the optimum grows even for easy problems?  

Let’s not forget that Spider’s competitors need much more improvements just to catch up with Spider.

Regards,

George

Rafael Davila
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There was no rain today, the next photo is just after his arrival. Photobucket The Next photo just before his departure, he parked his vehicle in the wrong spot and lost the wheels.

Photobucket

But local mechanics fixed it and even revamped it to his specs as follows, he left very happy.

http://www.youtube.com/watch?v=Vf-ZiAC5mIs

LA01 duration out of the box 11.55 hours, got 11.30 hours if after optimization the advanced option is applied with super float as main prioritization rule.

Photobucket

For LA16 I got 17hours and 27minutes, out of the box.

Regards,

Rafael

George Mejtsky
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Rafael,

Did Barack Obama get wet? And what about the Mavericks on Sunday? Barea is goooood!

Can you try to solve LA01 and LA16 by Spider? These are very easy to solve (easy to get the optimal schedules). Vladimir says: “Easy problems are not attractive.” So he will not solve easy problems. I think they could be important for us. If Spider finds the optimal schedules, or very close to the optimum (< 2% like FT06) then it is fine. However, if it is 3% or more then we have a small problem - to improve the schedule.

Vladimir,

I think Spider could be allowed to calculate schedules for FT10 or LA29 longer and find much better schedule. Why only 1, 2 seconds? As far as I know, the iterative heuristics, metaheuristics, work like this: they find the first schedule fast, in less than one second or so. They save the schedule, and continue in search for a better one. They search hundreds of schedules, until they find a better one, and save it, etc. In this way, they search and keep finding better and better schedules. They keep searching until a stopping criterion is reached. The stopping criterion can be the number of iterations, calculation time, or something else.

Vladimir, why not to allow users to select the calculation time as a stopping criterion? Rafael said: “About resource leveling time I am willing to wait up to an hour if need be, …” In this way on Resource Constrained Scheduling Options form, I could select 10 minutes or 30 minutes calculation time, and let Spider calculate for that time. I should get a much shorter schedule than with only 1, 2 seconds of calculation time. And we know the significant benefits for the company from this much shorter schedule.

In my job shop scheduling software, I do not have the calculation time criterion. I let the scheduling program run and run and search for a better and better schedule. I watch how fast the schedules keep improving. When I see that the rate of improving is slowing down too much, or I get tired waiting, I kill/stop the search for better schedules.

Regards,

George

Rafael Davila
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George,

Because of the rain, bikinis are temporarily out of service. Last year average rain was 40% over yearly average, 12 months of rain my friend, this year seems like another 12 months of even more rain, this is an Island so floodings are not big, water goes to sea very fast.  Tomorrow Barack Obama is coming to Puerto Rico, most probably he will get wet.

About resource leveling time I am willing to wait up to an hour if need be, so there is time to run a few schedule leveling on a day. We are talking about applications for the industry, on special occasions might be willing to wait more time. When we have a job in trouble many times the only way to compress the schedule is not by squeezing the resource leveling algorithm but by changing technology-logic and or preferential-logic, increasing resource availability, adding shifts and the like. Still no doubt efficient resource leveling algorithms are handy, ideally the optimal as they can make a substantial difference. As Vladimir said they can improve the quality of our schedules, with the use of these we can reduce idle time of planned resources.

Spider creates resource dependencies, perhaps this can be used to temporarily lock the schedule so schedule runs for logic without resource leveling can be performed fast, then after all logic modifications the resource dependencies can be released as to run true resource leveling without artificial links that might interfere. This functionality, perhaps unique of Spider, you might be interested to look at.

Agree resource leveling shall be developed by testing, I cannot see other way, in order for the testing not taking much time I believe relatively few activities schedules that create enough confusion to the algorithms shall be enough. Algorithms for our project type schedules as well as algorithms for production type schedules shall be developed and available on a single scheduling software as there is no such thing as the Universal Algorithm that works best for all schedules, to make it harder sometimes schedules combine both types of process. For the moment no such thing exists and even finding best prioritization strategy differs among the different software and even among different schedules within same software.

I am just a regular user that can use the tool as developed by the mathematical minds, I believe resource leveling algorithms can be improved, though not a simple task. I recognize sometimes by random I got some improvements, this is why I am asking for some way to record my settings and results as to make it easier to make some search by some kind of educated trial and error.

I believe Spider schedules and any software shall be compared to the other software, not against itself.

Sorry for not going any further but optimization methods is not my specialty, give me the tools and I will use them, by testing the tool and comparing to other software we will know how good it is.

Regards,

Rafael

George Mejtsky
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Rafael,

Thanks for “CANDIDATE RULES FOR MINIMIZING THE PROJECT DURATION” paper. I will read it soon. I just spent 10 minutes reading the beginning of it. I read many papers. If you have an interesting one, send it to me (george.mejtsky@yahoo.com). I am interested in production/project scheduling, resource allocation, simulation,  optimization, and bikinis.

I have a question about your “I would say computing time in these jobs should not be much of an issue, not even on a laptop.”  In what timeframe would you expect to get your solution/schedule? How long are you/others willing to wait? 2-3 hours? More? The longer you wait the better the schedule can be found.

As for your “If there are other algorithms that should be added because they are better under certain circumstances, why not adding these options.”  How do you want to find a better algorithm? By testing, right? We are now doing some testing of Spider. What tests would you recommend?

I think Spider is better than most project scheduling software in many, if not all, circumstances. Do you know a situation where Spider would be worse? If an optimization software is better than others in one situation, it is probably as well better in most other situations.  Spider is even better than most production scheduling software, I believe. It is the iterative heuristic of Spider that is significantly better than priority/heuristic rules of the others.

I would bet that the schedule found by a priority/heuristic rule is very close, if not worse, to a randomly picked schedule. That’s why, I proposed to include in Spider the random/average priority. Not for use by the users of Spider, only for internal Spider’s referential use to calculate an “average” schedule in order to see how far from the “average” schedule the normal/optimized schedule is. I would like to compare the “average” schedule with the schedules of competitors.

Regards,

George

George,

LA29 scheduling took a second or two.

The schedules we tried are not typical for projects and it makes Spider optimization less effective. In projects we always have converging paths and Spider iterative scheduling looks for these points (intermediate results) trying to achieve these results faster. In production scheduling benchmarks paths are independent. There are features that are necessary for production scheduling (like planning set-ups) and not for project planning, there are project management requirements that are not critical in production scheduling (many different calendars, part time assignments, complex dependencies, data uncertainties, etc.). But Previous Version Support is useful for both. It not only minimizes recalculation time. When new schedule is quite different than the one that was earlier approved the problems of resource reassignments, creating different supply schedule, etc. make the changes too expensive to be implemented.

If you will look at PP discussions you will find that few planners are trying to optimize project schedules, most do not load resources in their schedules at all. So project planning culture is even worse than in manufacturing. Spider is very popular in Russia and some other East Europe countries but when I speak about schedule optimization abroad very few people understand what I am talking about.

I will try most difficult benchmarks on return from my current business trip. We are involved in many projects and I am travelling a lot. Easy problems are not attractive.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

I like the idea of “Previous Version Support” to save time. I must remember it and use it in my software one day. I am a software developer of production scheduling systems with a similar optimization algorithm like Spider. My production scheduling system uses discrete event simulation for modeling and an iterative heuristic for optimization. I use a different name for iterative heuristics - metaheuristics.

How long did Spider calculate LA29?

You said: “I expected that the demand for good scheduling engine in manufacturing is much more urgent.” Well, I thought the opposite is true. As I know, manufacturing people want, in average, any fast schedule with no worry about the quality of the schedules.

As for your: “Genetic and similar algorithms are too slow for using in large project models but could be used in production scheduling where the number of activities is measured in hundreds, not thousands like in projects.” I thought that Spider is in the group of genetic and similar algorithms – iterative heuristics, metaheuristics. Why should other iterative heuristics be too slow for using in large project models? They can decrease the number of iterations too, like Spider. Even my iterative heuristic can do it and can be very fast with good schedules. Am I missing something?

I would say that an average production facility does not have thousands of activities; however, an average semiconductor wafer fabrication facility has hundreds of machines, thousands of orders/batches and thousands of activities all the time. But such facility is an extreme, very large and very complex. I worked for Japanese Sharp corporation developing scheduling software for their wafer fabrication facility in Japan. I used a parallel computer for faster scheduling.

Vladimir, there are more difficult benchmark problems than LA29. Other researchers are claiming that the most difficult benchmarks are ABZ7, ABZ8, and ABZ9. From my own testing, I must agree. In fact, I hate them because I tried very hard, and still I cannot get better results. You just want to improve your ugly schedules a bit, just a bit, but no mercy. Very, very frustrating.  Try those suckers, but I warn you do not get discouraged by the schedules.

Next time, let’s try some very easy problems like LA8-LA15.

Regards,

George

Rafael Davila
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George,

Might be of your interest;

CANDIDATE RULES FOR MINIMIZING THE PROJECT DURATION

http://dde.teilar.gr/attachments/581/trautmann%5B2010a%5D.pdf

Unfortunately Spider is not included and the resource leveling capabilities under these sample jobs cannot test how these algoritms perform under other real life modeling needs like variable partial assignments or other type of links. I understand only FS no lag relationship is used on these samples jobs, not even different calendars with different non-work days are considered. 

Real life is quite complicated.

As you can see in this report, bad performance by P6 is not as bad among the even worst performance of the others. I agree with the conclusion, among the tested software, none is good.

Vladimir,

Just in case you did not noticed, George said, "I must correct the optimum makespan for LA29. The optimum makespan is not known yet. Only the best known solution found so far is available, and it is 1130, if it is not an error."

I understand for different schedules the "best" algorithm might differ, precisely this is what I like about Spider, it provides several options that allow for prioritization and others that look for optimal. Because my jobs are usually on the range of 500 to 700 activities and US$20,000,000.00 not big jobs but very frequent in our construction market, I would say computing time in these jobs should not be much of an issue, not even on a laptop.

If there are other algorithms that should be added because they are better under certain circumstances, why not adding these options. I have no problem with having many algorithm options, prioritization is what confuses me.

I would welcome a table, to select several algorithms and prioritization options of their own, and the computer, while I am having a coffee, will run them all and output on the table the durations obtained under each option. Maybe even some suggested prioritization order can be displayed in parenthesis as an assistance for us to select these. If I can checkmark on the table the algorithms to be run then I can un-mark some and continue with only a few until I decide not to go further, but I will have a summary of my options and their results. Of course the idea about the table can be further developed, a table similar to other tables in Spider, where even directly parameters can be changed directly, where line would be loaded or recalled from the resource leveling dialog box, even un-statusing and sequential runs can be scheduled, and so on ..., just a practical table, nothing really new.

Best regards,
Rafael

George,

we use an approach that is similar to your proposal:

Standard option is traditional when the user selects resource allocation priorities,

Advanced is the first level, Optimization is the second level, Optimization Plus is the third level of optimization that do more and more iterations. When the standard or advanced option produce satisfactory schedules people can use them because the scheduling is faster.

We also added Previous Version Support to save time for further calculations and to make the schedules stable. When this option is selected the order of activity execution is kept like in selected previous version of the same project. Optimizing once you can use this option until the initial data changes become large saving time in project schedule calculation.

I entered initial information in days instead of minutes to be able to compare the schedules with the other PM softwares that do not schedule in minutes. The 5 days/week calendar is used.

Spider default schedule for 20 projects problem lasts 1337 work days, 15.5% longer than optimal:

Photobucket

Applying priorities the schedule can be improved. Next slide shows Project Resource Structure where activities belong to the same phase if they shall be done by the same resource. Applying phase priorities we can get better schedule like the next one with 1313 days duration:

Photobucket

P6 default schedule lasts 1707 days, 47.5% longer:

Photobucket

The best schedule of P6 achieved with Late Start priority lasts 1469 days that is 23% longer than optimal:

Photobucket

Spider file can be downloaded from http://www.mediafire.com/?77aq2txhyk35ci3

We could add further optimization if our users will demand it. But usually initial information in project management is much more uncertain than in manufacturing. The schedule shall be close to optimal and will be adjusted many times when additional information will become available. I expected that the demand for good scheduling engine in manufacturing is much more urgent. Genetic and similar algorithms are too slow for using in large project models but could be used in production scheduling where the number of activities is measured in hundreds, not thousands like in projects.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

About your “I am curious about the results produced for the same schedules by production scheduling programs.” As far as I know, the quality of production schedules is similar like in project scheduling because of similar algorithms (heuristic rules) dominate the field.

About your “Comparing Spider schedules with optimal we can find the ways for further improvements.” Spider’s optimization algorithm “is rather complex iterative heuristics”, you said. Iterative heuristics, such as tabu search, genetic algorithm, ant colony optimization, or bee colony optimization, have several parameters to tune the algorithm. The number of iteration can be one such parameter. The higher the number of iteration the shorter the schedule; however, at the expense of calculation time.

In Spider, this parameter might be set too low in order to produce schedules fast at the expense of the quality of the schedules. This might be even necessary for very large schedules. For smaller schedules, however, we (user or Spider) could set the parameter higher to get much better schedules yielding big project savings. Dynamic tuning the parameters of Spider’s optimization algorithm: What do you think about this simple Spider’s improvement? If it is possible to dynamically tune Spider then I have some more ideas for improvements.

Sorry guys,

I must correct the optimum makespan for LA29. The optimum makespan is not known yet. Only the best known solution found so far is available, and it is 1130, if it is not an error. I have some papers reporting 1130 (like http://docsdrive.com/pdfs/ansinet/itj/2007/222-226.pdf, Table 1 and Table 2, column Optimum, or www.soc.napier.ac.uk/~benp/dream/dreampaper13.pdf , Table 1, column Optimum), some 1132, 1134, and some 1137. As far as FT06 and FT10, the optimum makespans are 55 and 930, respectively. Amen.

Regards,

George

George Mejtsky
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Rafael,

For minimum makespans of the benchmarks, see, for example,

http://www2.research.att.com/~mgcr/doc/hgajss.pdf, Table 3, column BKS (3rd) or

http://faculty.bus.olemiss.edu/crego/papers/FF-JSSP.pdf, Table 1, column BKS (best known solution) and Table 2, column Opt.

I like your humor: “PS 54% off by P6 out of the box is not bad, I had worst expectations.” And people pay for it? Can you imagine their project savings if Spider was used? Is P6 an average software or there are some much worse? I think that is why we need comparisons, Olympic Games. We could have a simple-and-small-size set of PM problems, more-complex-and-average-size set of PM problems, and very-complex-and-big-size set of PM problems. And some medals for all competitors. No, I am not Spider’s salesman.

I got your FT10 file, thanks. And where is your youtube video of bikinis on the beach? I cannot find it in your post.

Regards,

George

Rafael Davila
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Posts: 4678

From a previous posting.

Spider Demo is limited to 40 activities but if you want to explore the 10x10 schedule maybe using the Free Spider viewer you can explore the files. You can download the file from the following link.

http://www.mediafire.com/?65yqw27jtx48ys4

Just download and open to explore the file.

About NBA basketball my team is the Boston Celtics, they did not make it into the finals so I am following Dallas Maverick because a local plays with them, JJ Barea, is not a regular player but still a good bench player.

http://www.youtube.com/watch?v=lV9z8czMTLg

Good things in life are not expensive, going to the movies is not, a hamburger on the BBQ is not, watching a game on TV is not, even watching bikinis on the beach is not, here it is a 12 month a year pastime.

Regards,

Rafael

George Mejtsky
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Rafael,

I downloaded the Viewer, and I cannot find FT10 or FT06 projects. There are 10 demo projects there. I never used this software. Can you help me?

You got it. it is LA29. Just 200 activities. Is it a small project? I guess so, if large projects have hundreds of thousands activities.

The minimum makespan for LA29 is 1157.

Are Dallas Mavericks as good as…..   let’s say…..    Spider?

Regards,

George

Rafael Davila
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George,

You can download the viewer from the following link.

http://www.mediafire.com/?g7jc418oz91498c

I downloaded it from the Spider users access, it is allowed to distribute unlimited number of viewers. It is intended mainly for distribution by registered users of Spider. They provide the Demo at their website but not the Viewer, perhaps to avoid too much traffic or maybe because Demo and Viewer should not be installed on the same computer.

You will be able to check my file and let me know if there is any error, even when I compared my results with Vladimir model there is always a possibility of error, a good excuse for you to explore the software.

I have never used the viewer as I jumped from Demo to full version within two weeks. 

I will try LA-29 but on Monday, tomorrow Sunday is for family time, will go to the movies and latter will watch the Dallas Mavericks NBA Finals game on TV. Will keep in touch.

instance la29
 +++++++++++++++++++++++++++++
Lawrence 20x10 instance (Table 8, instance 4); also called (setc4) or (C4)
20 10
8 14 2 38 7 44 0 76 5 97 3 12 4 75 6 66 9 12 1 29
0 43 2 85 3 82 5 38 4 58 9 89 8 92 6 87 7 69 1 80
3 41 7  7 9  5 0 43 2 14 4  8 5 61 1 84 8 66 6 48
2 42 3 74 4 59 6 41 1  8 9 73 8 43 0 96 5 19 7 97
7 23 8 42 4 37 6 55 0  7 5  5 2 70 9 38 3 75 1 48
8  9 6 43 7 31 4 25 5 73 3 95 0 79 2 72 9 60 1 56
1  7 5 21 8 53 6 16 4 94 0 97 3 78 2 64 7 86 9 31
2 65 6 59 7 85 1 33 4 30 8 44 0 61 3 86 9 63 5 32
6 45 2 44 5 61 8 93 1 30 7 90 9 84 4 11 3 16 0 60
4 47 7 36 8 31 1 49 3 20 2 28 6 52 9 35 5 11 0 32
2 77 4 10 9 68 5 17 0 85 1 84 8 20 6 49 7 74 3 34
0 17 5  7 1 85 3 29 2 17 4 76 6 59 8 71 9 13 7 48
6 87 4 39 8 43 7 11 2 15 3 32 5 64 0 19 1 39 9 16
5 33 3 99 6 32 4 91 8 82 2 92 9 99 7 57 1 83 0  8
3 91 5 39 2 69 8 27 7  7 6 21 1 38 9 62 4 88 0 48
2 67 7 80 3 24 0 88 4 18 1 44 8 45 9 64 5 80 6 38
9 59 3 72 6 47 4 40 7 21 5 43 0 51 8 52 1 24 2 15
3 70 2 31 6 20 8 76 1 40 7 43 0 32 5 88 9  5 4 77
4 47 5 64 9 85 3 49 7 58 1 26 0 32 8 80 2 14 6 94
5 59 2 96 0  5 7 79 8 34 4 75 3 26 6  9 9 23 1 11
+++++++++++++++++++++++++++++
Best regards,

Rafael

George Mejtsky
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Rafael,

You said: “I would dare to say on real life jobs Spider will be between 6% and 0% of optimal with an average of 3%, with a distribution close to 3%.” I wish we know how good our real life schedules are. I am afraid that your numbers are optimistic.

Consider this: there are more difficult benchmark problems to solve, like LA29 with 20 projects and 10 resources. I guess Spider’s schedule might be off by 20-30% in the LA29 case.

It seems to me that when the problem size is small, like FT06, a schedule of good software, like Spider, is very close to the optimum schedule. As the size and complexity of the problem grows, the schedules are further and further from the optimum, even for Spider. And the difference between Spider’s schedules and other software schedules grows and grows, as you said: “The bigger the schedule the more you will notice the difference between Spider and the rest.” I just like your analyses, so I read your posts very carefully.

Can you try LA29? Thanks.

Regards,

George

George Mejtsky
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Rafael,

What length was your schedule of FT10, what makespan? 16:37, (997, +7%)? Can you squeeze out a shorter schedule than Vladimir’s 16:36 (996, +7%) schedule?

I looked at your youtube videos of FT06 and FT10. It is a very fast calculation indeed. I downloaded 101.002.sprj file from MediaFire, but I do not know how to open the file, by which program?

I hope you did not make errors while inputing FT10 definition data. Compare it with the FT10 definition in the jobshop1.txt file (http://www.eis.uva.es/elena/Elena%20Perez%20Vazquez_archivos/files_optimaJSSP/jobshop1.txt)

Regards,

George

Rafael,

the best schedule is 930 minutes (not 926).

Spider best is 16:36=996 minutes, 7% more than the best schedule.

In P6 I tried individual priorities but did not try combinations of priority rules. The number of combinations is too large and potential improvement is small. 

Rafael Davila
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Vladimir,

Lets see if I understood:

If Spider is 9% off the best known solution then, Best Known Solution = 1010/1.09 = 926 min

Spider solution out of the box...= 1010/926 =>> 1.09 or 9% off
Rafael trial .........= 16.6167x60 = 997/926  =>> 1.07 or 7% off
Vladimir trial.........= 16.36x60...= 981/926  =>> 1.06 or 6% off

P6 out of the box....................= 1427/926 =>> 1.54 or 54% off
p6 best...................................= 1134/926 =>> 1.22 or 22% off

I understand you can improve on the 6% as you have not tried individual activity prioritization something I doubt P6 can handle. I also understand you tried all prioritization options that make sense in P6.

Best regards,
Rafael

PS 54% off by P6 out of the box is not bad, I had worst expectations.

1427.

But it can be improved by selecting other leveling priority. The best is 1134 days (minutes) with Late Finish priority.

P6 does not schedule in minutes. So I entered durations in days.

Best Regards,

Vladimir

Rafael Davila
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Anyone knows what P6 yields out of the box?

I do not have P6 but exported it into xer file so maybe someone can just load it and run the schedule resource leveling out of the box.

http://www.mediafire.com/?ae1vo0r5ajkr446

Rafael,

it is interesting that the sequence Optimization and then Advanced Super Float saves 1 more minute:

Photobucket

Thank you and Best Regards,

Vladimir

Rafael Davila
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George,

Sequential application of Optimization Plus and then Advanced using Super Float as Priority will yield better results, and this is without using activity priority. Don't ask me, trial and error, brute force, took me less than 2 minutes though.

http://www.youtube.com/watch?v=KqPzTLX_Gb0

What stands out is that even a schedule known to be difficult to optimize is not that far from optimum with Spider Project Optimization Plus out of the box. I would dare to say on real life jobs Spider will be between 6% and 0% of optimal with an average of 3%, with a distribution close to 3%.

No way you can consistently get there using preferential links as to mimic true resource leveling.

Believe me I have seen software that can go as far as 40% over Spider, say 43% over optimal, and this is unacceptable.

In schedules where partial assignments are allowed Spider stands out as it can even allocate for variable partial assignment. Partial assignments is the order of the day in construction schedules as well as in architectural design schedules where you have some crews or individual resources assigned to work on several long duration activities the same day.

Variable assignment is a refinement over fixed partial assignment that will make a huge difference when allowed.

Spider Demo is limited to 40 activities but if you want to explore the 10x10 schedule maybe using the Free Spider viewer you can explore the files. You can download the file from the following link.

http://www.mediafire.com/?65yqw27jtx48ys4

Regards,

Rafael

PS. The calculation time is always at a blink of the eye, as soon as resource leveling icon is clicked as seen on the video clip.

George,

when I wrote about applying priorities I meant priorities of certain activities or projects. When the scheduler receives automatic scheduling result he/she can try to improve it applying user defined activity/phase priorities (just numbers).

Spider does not have random scheduling and does not apply different priorities selecting the best result. Our algorithms were created for scheduling of very large projects (with hundreds of thousands activities) and shall be very fast to be practical. Both sample schedules that you proposed were calculated in less than one second time.

Applying random heuristics can produce good schedules but is not ptactical in project management. Project life cycle can be measured by years and the schedule is revised at least each week. It is necessary to be able to get the same or similar schedule after minor changes. Random priorities are hard to repeat.

Thank you for the benchmark reference. Comparing Spider schedules with optimal we can find the ways for further improvements.

I am curious about the results produced for the same schedules by production scheduling programs. I know PM software market but did not work with MES systems.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

Great! Thank you for your time and effort. How long was the calculation time? It looks like the second gold medal for Spider. When you have time, can you try to improve this schedule by applying priorities? Can you describe the process of applying priorities? As I understand, you select a priority or set of priorities and calculate the schedule, and then you select a different priority (rule, heuristic) and calculate a new schedule, etc. You repeatedly calculate schedules with different priorities, and then you select the best schedule found. Is this process the same in Spider?

In Spider, do you have some random priority (random heuristic) which would select randomly? I would like to know the length of the random schedule or an average schedule. If we know the average/random schedule then we could compare our best found schedule with the random schedule. We might find that our schedules based on priorities might not be better than the random schedule. I hope it is not the case.

The first production problem (6 projects and 6 resources, 6x6) is the smallest and one of the easiest instances found in the standard job shop scheduling benchmark set. This problem is called FT06 and has optimum makespan 55. Spider found the schedule with makespan 56 which is only 2% longer than the optimal schedule. Frankly, it is not very far from the optimum indeed.

The second production problem (10x10) is probably the most famous job shop scheduling problem, called FT10.  FT10 has optimum makespan 930 which is very difficult to find. Spider found the schedule with makespan 1016 (16 x 60 + 56) which is 9% longer than the optimal schedule. So there is enough space for improvement here. How much can you improve it? I think it is a very good schedule for the default "out of the box" solution. Can anybody find a better default "out of the box" schedule with a different software? I doubt.

I hope I made no errors in defining FT06 and FT10. You can find all the benchmarks defined in http://www.eis.uva.es/elena/Elena%20Perez%20Vazquez_archivos/files_optimaJSSP/jobshop1.txt. An additional information about the benchmarks is in http://www.eis.uva.es/elena/JSSP/index.htm.

In real world projects (large and complex), the optimum schedule is not reachable. Therefore, we do not know how far our schedule is from the optimum schedule. However, if we can get a random/average schedule then we can compare our schedule with it to make sure that our schedule is better than the random one, hopefully. That’s why, I propose to include the random priority rule in Spider, if it is missing.

Best Regards,

George

George,

Spider default schedule for this project lasts 16 hours and 56 minutes

  Photobucket

Resources are used as follows

Photobucket It looks like this schedule could be improved by applying priorities but I showed the default "out of the box" result.

Best Regards,

Vladimir

George Mejtsky
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Vladimir,

Thanks for trying backward scheduling. I kind of agree with Rafael that “The bigger the schedule the more you will notice the difference between Spider and the rest.” So here is a bigger production problem with 10 projects and 10 resources to show a bigger difference, I hope.

----------------------

Problem (10 projects, 10 resources):

P1: 10/29, 1/78, 2/9, 3/36, 4/49, 5/11, 6/62, 7/56, 8/44, 9/21.

 P2: 10/43, 2/90, 4/75, 9/11, 3/69, 1/28, 6/46, 5/46, 7/72, 8/30.

 P3: 1/91, 10/85, 3/39, 2/74, 8/90, 5/10, 7/12, 6/89, 9/45, 4/33.

 P4: 1/81, 2/95, 10/71, 4/99, 6/9, 8/52, 7/85, 3/98, 9/22, 5/43.

 P5: 2/14, 10/6, 1/22, 5/61, 3/26, 4/69, 8/21, 7/49, 9/72, 6/53.

 P6: 2/84, 1/2, 5/52, 3/95, 8/48, 9/72, 10/47, 6/65, 4/6, 7/25.

 P7: 1/46, 10/37, 3/61, 2/13, 6/32, 5/21, 9/32, 8/89, 7/30, 4/55.

 P8: 2/31, 10/86, 1/46, 5/74, 4/32, 6/88, 8/19, 9/48, 7/36, 3/79.

 P9: 10/76, 1/69, 3/76, 5/51, 2/85, 9/11, 6/40, 7/89, 4/26, 8/74.

 P10: 1/85, 10/13, 2/61, 6/7, 8/64, 9/76, 5/47, 3/52, 4/90, 7/45.

----------------------

For understanding how to read this notation, see my previous problem.

Best Regards,

George

George,

we do not make our optimization algorithms public. It is rather complex iterative heuristics. We did not compare Spider schedules with Preactor's. This information we got from our customers in Brazil.

I tried backward scheduling but the result was not improved. It is possible to try options applying user defined priorities but it is time consuming and hard when the schedules consist of many thousands activities. We tried to make the default schedule as close to optimal as possible with very limited number of iterations. Resource scheduling shall be very fast to provide good schedules at the start of each shift and the schedules where Spider is used are usually large.

Best Regards,

Vladimir

Mike Testro
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Hi George

I would love to help but I am heavily involved in an arbitration.

You can download a 30 day trial version of Asta PowerProject v 11.04 at

www.astadev.com

Best regards

Mike T.

 

George Mejtsky
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Vladimir,

Thanks for your information about activity duration in project scheduling. I am still learning and learning. Raf selected Optimization Plus method on the Resource Constrained Scheduling Options form. How does the method optimize the schedule? Raf mentioned that perhaps the method searches some prioritization rules under several layers (iterative heuristics?). By the way, why Spider schedules are much shorter than Preactor schedules?

Rafael,

Can you run my problem (6x6) again and this time with Backward Direction (instead of Forward) set on the Resource Constrained Scheduling Options form? You might find a shorter schedule with 55 minutes total duration, I hope.

It would be very useful if somebody would solve Vladimir and my problems by other project management software, like Mike with Asta. So we could compare them by quality of resource allocating.

Best Regards,

George

Rafael,

thank you for your help.

George,

usually initial information for such projects is not activity durations, but volumes (quantities) of work to be done on activities and productivities of assigned resources. Activity duration is calculated as the ratio of volume of work and total productivity of all assigned resources.

You can also assign skills necessary for doing the job. If resources that have necessary skill are known Spider will select resources to be assigned basing on default or user defined priorities and resource availabilities. In this case activity durations are not known before scheduling because different resources have different productivities and durations are calculated in the process of project scheduling when assignments are selected.

Best Regards,

Vladimir

Rafael Davila
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George,

It takes fractions of a second, perhaps faster than the time it takes your sight to follow the cursor. The software is designed to work with thousands of activities per job and a few jobs opened at the same time.

Look at the following video screen capture.

http://www.youtube.com/watch?v=HRTlsExVCGo

It was done selecting the Optimization algorithm, is 100% automatic. The others not necessarily will provide you with a shorter schedule, no matter which prioritization rules you use. The bigger the schedule the more you will notice the difference between Spider and the rest.

At times it is better to use the other methods as to have some control, especially when using "Apply activity prioritieas" and "Apply phase priorities" in addition to other selected on the Priority selection box. Then when in trouble go to full optimization, here the Priority selection box will be dimmed and the software will look for full optimization without regard to a pre-defined priority, perhaps in Optimization modes it searches some prioritization rules under several layers, if this makes sense.

The following screen will show you the resource leveling options screen.

Photobucket

You can download the Spider File for your use with the demo so you can explore it yourself and find out if there is any error.

http://www.mediafire.com/?a1iw802b74gema2

If you do not work multiple jobs linked together or sharing resources, each job thousands of activities Vladimir might help you select the best option for your needs, it is a scalable product.

Best regards,

Rafael

George Mejtsky
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Rafael,

Wonderful! Congratulations! It is a very good schedule. It looks like the gold medal will go to the Spider team. If the Asta PowerProject team, or another team, does not find a shorter schedule, gold will go to Rafael for the Spider team.

Rafael, did you produce the great schedule out of the box (without applying user defined priorities)? How long was the calculation time?  

Anyway, I must thank you for your time and effort.

Cheers,

George

Rafael Davila
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I got it with 56 minutes total duration.

Photobucket

George Mejtsky
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Hi Vladimir,

Thank you for your detailed response and your time with the problem (4 projects and 3 resources). Why Spider schedules are much shorter than Preactor schedules? I am trying to find software which is better than others, producing shorter schedules than competitors can produce. I do not care about optimal schedules, I only care about just better schedules than others can produce. How do iterative heuristics of Spider find a good solution in this problem of yours?

Mike, thanks for participation in this discussion. Is your schedule shorter than 51 minutes?

Vladimir, can you try another problem with 6 projects and 6 resources? No tool change time (set-up time) is included, and each resource has capacity 1 (quantity 1).  To describe the problem, I will use a short notation: resource number/duration. For example, 2/1 means the operation needs resource number 2 for 1 minute.

 --------

Problem (6 projects, 6 resources):

P1: 2/1,  6/3,  1/6,  3/7,  5/3,  4/6.

 P2: 1/8,  2/5,  4/10,  5/10,  6/10,  3/4.

 P3: 2/5,  3/4,  5/8,  6/9,  1/1,  4/7.

 P4: 1/5,  6/5,  2/5,  3/3,  4/8,  5/9.

 P5: 2/9,  1/3,  4/5,  5/4,  6/3,  3/1.

 P6: 1/3,  3/3,  5/9,  6/10,  4/4,  2/1.

---------

Read the first line like this: Project P1: the first operation needs resource R2 for 1 minute, the second operation needs resource R6 for 3 minutes, then operation 3 needs resource R1 for 6 minutes, etc. Notice that each project uses each resource but in a different sequence. In the Vladimir problem, all 4 projects have the same sequence of resources (R1, R2, R3).

Mike, can Asta PowerProject find a shorter schedule than Spider Project?

It sounds like the Olympic Games in Project Management software.

Cheers,

George

george.mejtsky@yahoo.com

Mike,

I did not mean George example but general production scheduling.

If I don't know the next work then I don't know necessary tools and what time is necessary for tools adjustment. So I cannot add changeover activity because don't know what work will be next and what time will it take. It is not actual in project management but may be critical in production scheduling. I think that we will add this feature to Spider since we have more and more customers in manufacturing.

Did you try Asta with my example?

Best Regards,

Vladimir

Mike Testro
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Hi Vladimir

I did not see any item about changing tools in Georges thread - just applying Resource R1 to a number of different tasks in different projects.

That is the same as allocating Crew 1 to different sections of a pipeline.

If there is to be a time required for tool change over then that could be done with a simple task set between changeover tasks or alternativel a lead time on the link if the calendars are compatible.

Best regards

Mike T.

George,

Spider Project is used for production scheduling in Russia, Ukraine and Brazil. Recently I received a letter from Brazil where it was written that Spider is used for production scheduling instead of Preactor because Spider schedules are much shorter.

But Spider still does not model time necessary for changing the tools when there is a need to do different type of job. This is serious restriction if these times are large.

You described famous NP-complete problem and Spider does not guarantee the optimal solution but its iterative heuristics finds the solution that will be close to optimal. I added fourth project (machine) to the example below to show what Spider will do solving your task.

Mike, I am curious if Asta will produce the same (or better) schedule for the same problem out of the box (without applying user defined priorities). Please enter the same data into Asta and show us the result. Photobucket Regards,

Vladimir

Mike Testro
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Hi George

I will be interested to hear Vladimir's response but this is a matter of routine resource allocation in Asta PowerProject.

Best regards

Mike T.

George Mejtsky
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Vladimir,

I respect you, and I agree with your postings. In fact, I cannot find even one sentence where I would not agree with you. You proposed to suggest hard tasks so I will try my luck. I am coming from production scheduling field, and I wonder whether your Spider Project software can solve some of shop scheduling problems. I will describe such problems by project scheduling terms.

I have several projects: The first project P1 starts with activity P1A1. The activity P1A1 requires resource R1 for p1a1r1 minutes, and then the next P1 activity A2 requires resource R2 for p1a2r2 minutes. The third activity A3 of P1 requires resource R3 for p1a3r3 minutes, etc. The second project P2 starts with activity P2A1 requiring resource R1 for p2a1r1 minutes, and then the next P2 activity A2 requires resource R2 for p2a2r2 minutes, etc. The third project P3 starts with activity P3A1 requiring resource R1 for p3a1r1, etc. So each project has a sequence of activities and each activity requires a resource for a fix time. Each resource Ri can be assigned to only one activity (resource capacity is 1). This is a resource allocation problem. The question is how to allocate each resource so that to minimize the overall completion time of all projects.

I guess Spider Project software can solve this type of problems. Can you tell me if and how it can be done in Spider?

Best Regards,

George

Rafael Davila
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Vladimir,

Yes, it is a useful visual report, but my point is that it shines in linear projects.

And while contrary to other linear diagram tools, in Spider all the PDM functionalities are also available. The PDM metrics matter as much or even more, still if a linear job, the Graph is just a representation.

Best Regards,
Rafael
Rafael,
for high rise buildings it is also very useful.
The metrics consists of floors (or levels like in your example) and Lnear Diagram shows what work at what floor will be done at what time.

But in any case it is just one of many reports that may be used along with the Gantt Charts.

Best Regards,
Vladimir
Rafael Davila
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Well, it shines in linear jobs such as pipelines and roads not in building construction.
Rashid,
if you will download Demo version of Spider Project from http://www.spiderproject.ru/demo_e.php you will find there sample project that includes construction part (a small part of the resl project), financing, and future profits.
In this project you will find multi-resources (crews) assigned to construction activities, activity durations that are calculated basing on their volumes of work and assigned resources productivities, cost components and cost centers, cash flows that includes expenses and financing, expenses and incomes that are calculated with cost discounting, materials that are assigned per work volume units, resources that work in shifts. In this project you can try cost and material levelling.

It is small part of many unique Spider Project features but you will not be able to repeat this project using other softwares including P6.

Spider Project optimizes resource constrained schedules. Recently Rafael uploaded small and simple project but P6 produced optimal schedule (the same as the schedule produced by Spider Project) only after manual assignment of activity priorities. Impossible in large projects. And in many real projects the difference of schedule durations is huge.

I can add skill scheduling, trend analysis, etc.

If you ask about some reports I suggest to look at Linear Diagram - it is Time-Location Chart that is one of many projectt reports.

If you want to see something specific please ask.
This thread was created for challenging Spider Project - I am still waiting for hard tasks. If you need something that other PM software does not do, ask if Spider Project can do it. Two options - I can explain how Spider does it, or you will suggest Spider Project improvement.

Best Regards,
Vladimir
Rafael Davila
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01
03
03
04
Rashid Iqbal
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Vladimir,

You sound well conversant with both spider and primavera...can you attach a layout of spider that you think P5 cant produce. Thanks please do it at your convinience.

Regards
R
Safak Vural
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Dear Vladimir,

I personally request Russian papers or presentations if there are any. My Russian is not good enough for that kind of stuff but I can make them translated at my work easily.

Regards,

Safak VURAL
Hi Safak,
I am sorry that there are few Spider papers and presentations in English. Don’t forget that it is Russian software. The documentation that is created by Russian corporations is in Russian and Brazilians publish their papers in Portuguese.

Spider site contains papers and presentations mostly made at different PMI events. At these presentations I talked about the methods that we use trying to avoid mentioning Spider. Spider Project was and is used for management of many oil&gas construction projects in Russia, Ukraine, Belarus. Examples; Caspian Pipeline, Blue Stream, Nord Stream, East Siberia – Pacific Ocean, and other pipelines, development of Bovanenkovo Gas Field.

Best Regards,
Vladimir
Rafael Davila
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Safak,

In Spider Project you can run Scripts from outside Spider so you can have access to all the power Reference Book provides. If your software can access text files then it can communicate with Spider Project, if I understood correctly what Vladimir once mentioned in one of his postings.

Perhaps it is not a good idea to have a direct link to the database fields as this can corrupt integrity of the data, Reference Books provides the link. Field relationships in CPM are not as simple as relationships within a database.

I do not have such a requirement in my jobs but Spider can provides for the most demanding requirements, on my part you are welcomed with your questions, I believe this kind of questions were missing and your postings will add value to the discussion.

If I am right maybe in a future we will be exchanging script templates to communicate with Oracle/Primavera/Microsoft/SAP/....

Best regards,
Rafael
Safak Vural
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Dear Mr.Liberzon and Mr.Davilla,

First of all I want to congratulate you for the battle you continue to make people hear you. I wish you to continue your way and conquer more castles in project controls territory.

I am trying to follow this thread with playing in your demo. Everything seems so perfect user friendly and solution oriented in software. Personally ASTA – Power Project seems good scheduling software also. But the ORACLE® and PRIMAVERA® are offering some other aspects as well. Also all my clients are commitetd to them. In many projects I touch or hear (from colleagues etc.) cost control - oracle rdb, estimating and quantity surveying sql rdb, HR and personnel time recording oracle and sql rdb, QA/QC sql rdb ……. List can be longer. Data collecting is becoming easier and IT works is becoming user-friendly everyday. SPIDER® has to fight with these kinds of integrated packages in the market also due to availability of direct integration for PRIMAVERA® products with that kind of databases.

Can I challenge SPIDER® team not with software with studies, papers, procedures etc. If you check all major construction companies in OIL&GAS almost all their project control documentation based on duration based CPM where majority of them referencing PRIMAVERA® directly.

Can you provide more documents about projects which used SPIDER® and Critical Chain Project Management (Like Urucu-Manaus Gas Pipeline)? It is not easy to find papers, studies etc. supporting Critical Chain. Can you reference papers? Can you create a package that the Project Controls for Critical Chain approach with all main and support processes including inputs, outputs, responsible items, customers, where you can include SPIDER® in one or more of this processes. I checked all publications SPIDER® web page but I cannot find anything which is answering the questions above. If there are academic references you can provide I will be happy also. I will try to access them from my university library in my vacation times at my hometown.

Regards,

Safak Vural
Rafael Davila
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Vladimir,

You got it very right; my question was about scalability and transfer of resource definitions.

The great thing about it is that scaling is defined at the activity level so when scaling your fragments only scalable activities will be scaled. If you have a fragment for mat foundations, you would transfer several activities whose duration will depend on the scale but others will not be changed such as concrete curing.

Maybe you cannot say all activities will either be fully scalable or not scalable, a few will fall in between. I would dare to say over 95% will be covered and the remaining with a simple adjustment can be handled. Hey you are transferring even resource definitions.

Please don’t complicate fragments, keep is as simple as it is, cannot get any better.

Best regards,
Rafael
Rafael,
I don’t know software packages that have similar functions.

This is the way we create complex project models.
Fragments describe typical work packages for certain work quantity (1km, 10m3, etc.). Inserting the fragment project planner defines the real volume of work at the certain work package and fragment data will be adjusted automatically.

With fragment library it is easy to create large project models:
Project Planner creates WBS, then inserts project fragments at work packages level, then creates links between activities of different work packages. Everything else is already there - resources, costs, calendars.

Fragment Library is the main element of the corporate PM system.

Best Regards,
Vladimir
Rafael Davila
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Vladimir,

Thanks you for your briefing on the application of fragments.

…”For repeating sets of activities we suggest to use the typical fragments library that consists of small projects that model typical sets of works. You can use insert other projects as the new phases. This is the way we use working with the fragments. The software asks what to do with activity codes and volumes. Activities may be scalable or not (look at activity properties). If scalable then their volumes, durations, etc. will be multiplied by the user defined number”.

I noted that even resources definition is transferred so if new resources are required these will also be transferred.

This feature of being able to scale the fragments is something I have never seen before. With Primavera SureTrak I did not even had the basic functionalities of fragments. Do you know if such “scalable” and transfer of resource definitions are features available in other software?

Best regards,
Rafael
Scarllet Pimpernel
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Dear Raffy D,

Please do not impose to Raffy what to do and what not to do.

Raffy Davila did a good work by helping the PP community understand Spider Project Management better than before. No other PP member have ever done what Raffy did here. And it did give the PP community a hope that somewhere there is a better construction project management software than Primavera P6.

If you really feel that your software is the best ever, you can always plead for your case here in PP.

Remember the tenets in PP is Freedom. and through freedom only mankind can achieve the best ever.

Thank you,
Scarlett
Hi Scarlett,
Spider Project is already the software of choice for construction project management in Russia and is used by most Russian construction companies. It is also used by large corporations involved in construction of plants, dams, and other facilities. But it is also used in other industries including IT.

We know that any project management software is a tool that shall help in managing projects. Without proper project management system the software will be used for drawing charts and in this case Spider Project advantages are useless. So we help to implement not just Spider but project management systems for our customers. Our company is involved not only in the software development and customers support, but also in consulting, training and project management. We manage construction projects for our customers and thus have very good understanding of construction management needs.

But we do not believe in advertisements. We never marketed Spider Project. Our promotion – happy customers who told others about their satisfaction. In any case we are not able to compete with Oracle in software promotion and we do not want to sell the software to incompetent buyers, who will use it for drawing.

We have branches in other countries with very competent managers. They use the same approach. It works but it is a slow way. We have customers in 27 countries and many of them found Spider Project in the Internet. They used other softwares but understood Spider Project advantages. Our potential customers are those who want better planning, shorter schedules, resource usage optimization. It is a minority but we are interested to work with this minority. We are afraid just to sell the software, it is dangerous for Spider Project reputation.

So we have no strategic plan for Spider Project promotion, we just make it better and better each month and hear customers needs. I’ll be grateful for your ideas.

Thank you and Best Regards,
Vladimir
Raphael M. Dua
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Scarlett P

What a narrow view of the world of Project Management software you have

If you visit the Planning Engineers site www.planningengineers.org and go to the survey tab, you will see a large number of software packages.

My own software Micro Planning X-Pert for Windows and Mac happily keeps selling to all industries and I must admit I have seen in recent times an upsurge in small to medium sized builders buying my product, especially as they now seem to be moving towards earned value and of course resource scheduling.

I would suspect that more than 80% of users do not want the complications of SPIDER, P5 OPP, Astra Power PERT

My client base justwants to plan and schedule quickly inexpensively and get the best results with the need for a vast SQL and DB infrastructure

Rafael

Frankly I think it is time to stop this non stop let’s Challenge Spider and get on with some work for your client

The challenge for our limited time now is to provide some help to Haiti and help them rebuild and do something practical.

I am looking at trying to offer the UN some Planners and Schedulers using our skills to help the people on the ground, as we did for WHO the 2004 Tsunami in Indonesia and Asia



Raphael
Scarllet Pimpernel
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Good Day to all,

I did read this tread and got lost along the way. With 300++ post and 4,500++ viewers, whats now?? How will it benifit me or the common planner?

to shoot down Primavera, I seems to agree with one post that Primavera indeed was highjack by IT. Primavera started as a construction project management software and end as an IT project management software. It should not be a surprise knowing Oracel bought Primavera.

So, there is no point in criying against Primavera, it will just die a natural death, irrelevant to construction project management.

I would also say, forget Microsoft Project for idiots.

But there is new hope because we have Spider as a project management software.

My question to Vladimir: what is your strategic plan to make Spider the software of choice for construction project management professional?

Thank you,
Scarlett
Hi Rafael,
if you will corrupt the database using reference-books it will be very useful for Spider improvement. Thank you for trying and inform me if you will find the way to do it.
The reference-books can be used for anything like creating the dictionary of activity and resource names that can be used for automatic creation of many languages project model (English, Spanish, Russian, etc.).
I will discuss deleting option with our programmers when will return to Russia.
Best Regards,
Vladimir
Rafael Davila
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Vladimir,

By creating a custom field and a formula I can reassign ID codes to my activities with ease but reading about Reference Books I crossed with the statement that it is also possible to transfer data to a key field in addition to transfer fields. I used Reference Books as another way to change my activity ID’s, a key field, and it worked, this will make it easier to change activities ID’s in all my versions or prior updates.

By the way on purpose I duplicated some values and did not transferred duplicates, some day I will find a way to corrupt the database using Reference Books. Perhaps if you add the functionality to delete records using Reference Books the banana peel will work, like Wile E Coyote I will keep trying.

Best regards,
Rafael
Rafael Davila
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Vladimir,

Probably I would say add the following transfer Method: "Delete matching rows" to the Data Transfer Setup dialog box. By matching I mean matching key field only.

With all the existing options for "Transfer to" and "What to transfer". As to have same control on these two options. Maybe "Column type" dimmed when selecting this new option, not sure about Data Transfer Options buton.

The basic idea is not only being able to add rows but also to delete multiple rows and then by clicking on any other option for "Transfer method" you can get them back using the same Reference Book.

I understood your proposal and believe that what can be done at the moment is far superior to what can be done with other software. It is just that Reference Books seems so logic it is not difficult to imagine using these to systematically delete table rows (in the hundreds), to use them to repeat the deletion in other schedule update versions and to use them to restore the deletions without missing a single deletion and restore.

Best regards,
Rafael
Hi Rafael,
though this is rarely required it is easy to add new option to others.
So they will include:
1) Modify existing objects,
2) Modify existing and Add new objects, and new
3) Replace all objects.
Did I understand your proposal properly?

In my previous post I explained how it can be done at the moment.

Best Regards,
Vladimir
Rafael Davila
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Augustin

Spider Project structure, screens, functionalities... are so well designed that will allow the developer to improve on it for many years to come in ways a few others will be able.

If I used Primavera SureTrak for 10 years and it was never improved, most probably I will use Spider for twice these years.

Vladimir,

If good for 3,200 additions then why not also good for 3,200 deletions.

If I want to apply the deletions of say 20 links to 8 versions, for forensics, it would be 160 deletions, if I want to apply it to 20 different schedules that used the same logic, also to 8 versions of each it would be 20x20x8 = 3,200 deletions.

Best Regards,
Rafael
Hi Rafael and Augustin,
yes, reference-books can be used as backups.
An example:
You created reference-book of the project hard dependencies.
Then you added soft dependencies.
Then you decided to delete all soft dependencies and restore the initial network logic.
For this you shall open Links table, select and delete all links, then open reference-book with the stored links and transfer all of them to the project.

Best Regards,
Vladimir
Augustin Purnus
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Hi Rafael,

You are right. I explained only what can be done now.
You are talking about a new feature which requires some developments. I don’t know what means from this point of view, what effort should require, but thinking “out of the box” is the best way problems can be solved.

What I really love at Spider Project Team is that if there is a new feature required by the users which improved the solution, than they will do it very quickly.

Best regards,
Augustin
Rafael Davila
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Augustin,

The data transfer default might be to transfer to existing rows only but you have the option to create new rows as well as full transfer. I was thinking in an option to delete matching rows. In this way you can apply your deletions to any previously updated version as well as to restore it back without the need to create additional versions and without the need for additional backups; your backup is the Reference Book per se unless you want to back it up also.

Also if you want to undo it would be a single or a few protocol of actions lines.

Data Transfer

Remember we all have our particular needs and ways of doing things, keep sharing yours, we all need other point of views.

Best regards,
Rafael
Augustin Purnus
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Rafael,

The Reference Books will transfer data. If it is empty than you will transfer “nothing”.

It is easier to simply go to the Links Table, select all links and delete them. Then, transfer the new links. You can create different links in different tables and transfer them into the project. To keep the scenarios, save as with different version numbers.

I was just playing with Switch type of activity and Switch Condition for the links. It shows similar with the decision tree (if, than, else). I had last year a project where the client wanted to see different activity sequences based on a decision point, like Switch. I didn’t have at that moment such feature, but I’m happy it is available now. However, I look forward for the improvements Vladimir told.

Except Pertmaster and probably Open Plan which apply Monte Carlo and Conditional Branches, I don’t know other solutions with such a feature.

Best regards,
Augustin
Rafael Davila
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Vladimir or Augiustin

I can use Reference Books to transfer links (precedence/activity links) from a table. What if I want to use the Reference Books to erase these links, can it be done? In this way I can toggle on and off unlimited combinations of links to perform what if analysis for my links.

Does it make sense to you?

Best regards,
Rafael
Hi Rafael,
we use Spider Project with Windows 7 at our office and did not meet problems yet. Spider Project also works without problems with Windows simulators for MACs and Linux.
I do not expect problems but let us know if you will meet any.

Switch activities will be improved soon. Now you can manually decide if it is in position Yes or No and depending on this position different network branches will be used. Later Yes or No will be calculated basing on user defined conditions. I expect that these improvements will become available in February.

Reference-books permit to set corporate standards, rules, pools, and a lot more. I just cannot imagine how PM corporate system can be implemented without norms and standards.

Best Regards,
Vladimir
Rafael Davila
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Augustin Purnus

I followed your advice for looking into Reference Books, I thought it was merely for job templates and found it is much more powerful and safer than using OBDC to connect to the database.

Because it is so powerful it ramifications are many, you can even use it to control user access down to the individual field level; for the moment I will skip this part on users’ access and continue with other applications for the Reference Books.

Then I will explore the Portfolio functionality and will eventually have a few questions related to shared resource allocation and project updating under a portfolio.

In the in-between if you can give me some hints about the new switch activity I would appreciate it as the English Help for this functionality is lagging a few months of updates and could not find an English paper on it at the Spider Site. I understand this is just the start as this functionality will be further expanded, some fun with it will do no harm.

Best regards,
Rafael

Augustin Purnus
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Rafael,

From my experience, changing a working Windows version which a new one without knowing its behavior is very challenging. It will give you nothing else than time consuming. When I changed my computer it came with Vista. It was a disaster, and therefore I downgrade the system to XP. I am happy with it.

I think Vladimir will tell you there is no issue, or it will be solved fast.

I wonder what other challenges did you find for Spider Project.

Best regards,
Augustin
Rafael Davila
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Vladimir,

I am buying a new PC, therefore I am interested into knowing how compatible Spider Project is with Windows 7 Pro 32 Business.

I am ruling out Windows 7 Pro 64 but would like to know also about it. I understand some hardare drivers for a 64 bit operating system can create issues and wonder about the HASP key, though believe this should not be an issue.

Best regards,
Rafael
Rafael Davila
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Mike,

In Spider Project they are called signals, I am not there yet but will be looking on how to set them green when our little frogs start singing.

Cells in the user fields can be marked with markers of various colors and shapes; this notifies the user that various values in the given field get in certain intervals. A set of intervals, to each of which a certain color is appointed, is called Signal

This functionality is also available in MS Project as well as in many others.

If you set a marker for every possible range then it is too much, better assign a marker to a couple of ranges to be highlighted, otherwise by highlighting everything the purpose is lost. Combine shapes as to differentiate, not just colors, also consider using a few columns for your markers to make it easy to search your ranges.

Best regards,
Rafael

P.S. My personal HP Laserjet is color blind, only knows B&W.
Mike Testro
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Hi Rafael

I liked your little frogs - we had a similar chorus outside our bungalow in Nigeria.

Best regards

Mike Testro
Mike Testro
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Hi Gentlemen

I have just started using the PowerProject traffic light symbols where you set up parameters and the light in the column changes colour.

For instance if the formula compares planned end with progress end on any particular task and the spread is 5 to 10 days difference then:

Green = anything up to 5 days
Amber = anything between 5 - 10 days
Red = Anything over 10 days

The symbol shows on any level and with multiple projects so management have a quick and visual reference as to where there may be problems.

It can be set up to show reduction in float if there is no baseline.

Best regards

Mike Testro

Rafael Davila
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Better than in a report, it will be available always when you want it and error free.

Happy New Year
Rafael,
very soon (I think that in January) this filter will become standard. So it is not necessary to create special formula.
Happy New Year!
Vladimir

Rafael Davila
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Vladimir,

I am creating a filter for out-of-sequence but first need to verify the following formulas I will transfer along with the custom fields with ease using Ref.Books. Are these correct?

OOS2

It might be that EarlyStart is the correct field to use in formula 5 as might differ with AsapStart when split is allowed or after progress, just could not find the definition/formula for the EarlyStart field.

Best regards,
Rafael
Rafael,
I don’t know P3 limits for concurrent users. I only remember that the number of project activities is limited by 100000. There are also limits on the project and activity code lengths and the number of calendars.
Best Regards,
Vladimir
Rafael Davila
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User Code

Vladimir,

You are right, it is not limited to four characters but to hundreds, the same as for activity codes. I could not find the limit.

Do you know P3 practical limit for concurrent users? Just as a comparison for my knowledge and the knowledge of my clients.

Best regards,
Rafael
Rafael,
I don’t think that you will meet any problems with the reference-books. They are used in Spider Project from the very first release in 1993 and never caused problems for Spider users. They may be created from the Excel spreadsheet but then become internal.

I don’t remember about four characters. Actually Spider Project has no limitations on any code length.
Spider Project uses the model of group work when the database is replicated in accordance with Responsibility structure and can be updated at any moment collecting current data from the unlimited number of project users. I don’t know the limits, we never met problems with this. But actually there are moderate number of people that work with the same models. I don’t remember the customer who has more than two thousands projects in one portfolio and more than several hundred users that work together with the same model.

Best Regards,
Vladimir
Rafael Davila
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Vladimir,

For your knowledge, I am starting to use Corporate Reference Books. It worked fine for my transfer of resource definitions and assignments from my sample job with my resource loading into your file modeling payments but without my resources.

Because previously I had an unpleasant experience with P3 when linking the database to a spreadsheet using ODBC Btrive drivers to the point it locked the software and I had to reformat the hard disk and re install everything I will explore this functionality to see if something like this can happen. Up to now not even intentionally it has allowed me neither to corrupt the data files nor to lock the software.

If I cannot find a way to corrupt the database nor to lock the software with this functionality it will not be of my occasional use but of frequent use as it is by far more functional than just linking to an external spreadsheet.

I read in spider Help you can set up a four characters code for your users, this includes the alphabet and special symbols, so in theory if 40 possibilities per character yields over 2.5 million users (40x40x40x40), is this correct? And what about concurrent users, how many is the theoretical and the practical limit? Can it be as long as there is a record available, not still locked?

Best regards,
Rafael