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How to model material carriage?

17 replies [Last post]
Carlos Arana
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Good day, I want to model a typical work fragment for material carriage. In the project, we use cat 740 articulated trucks for carriages: [IMG]http://upload.wikimedia.org/wikipedia/commons/9/9c/Cat740Ejector.jpg[/img] The CAT740 consumes oil, diesel and tires. It also has its own operator. I modeled a multicrew wich uses the CAT740 and an operator for CAT740. Now, what I don’t know how to add into the model is the Diesel, oil and tire usage. From the budget I got the following data: 1 hour of articulated dump truck usage consumes: 22.71 liters of Diesel 0.244 liters of Oil for diesel engines 0.000167 lots of tires (A lot of tires includes the 6 tires) And from the Caterpillar Performance Handbook I got the following data: Top speed: 54.7 km/h Max capacity (Should not be exceeded): 39.5 Ton; 18.5 m3 (struck); 24 m3 (Heaped 2:1) The carriage time from each material center to each placing site will vary depending on road lenght, but how do I model the carriage inside Spider? Or is this an excesive level of detail? Then, how can I model the material carriages?

Replies

Carlos,

I see too many examples when companies pretend to manage their projects using PM methods and tools.

Actual implementation of project management based on thorough planning and control is still rare and can be implemented only from the very top of the organization. If the owner or top manager does not know what to require he/she will get nice reports that show what is desired by those who prepared them.

So you will be able to implement serious approaches to management only with top management support.

Best Regards,

Vladimir

Carlos Arana
User offline. Last seen 50 weeks 4 days ago. Offline
Joined: 6 Jun 2009
Posts: 178

Thanks for the advice.

Vladimir:
I want to learn Spider since I perceive it as a world of possibilities. In P3 I've started finding limits. The "natural" next step would be P6 but I learned P6 before P3 and I know it has unnecessary complications. Making a remembrance, having basic skills in MSP opened me the door to P6 training and then, attending a contractual requisite I ended using P3. In the practice there is only one P3 scheduler in this project, everything else is made using MSP. The schedule is perceived as a contractual document to look at, not as the tool for project controls it should be.
I will make my daily job using P3, but in my spare time I will keep testing Spider. I have small projects from other (investment) forum which I can use to make tests.

Rafael:
Being the only P3 scheduler in this project, my only point of comparisson is the people in this forum. I think that Vladimir is right, I should cultivate other type of skills while I'm at this project. The irony is that, being a software from 10 years ago, P3 and CPM are High-tech here. About the schedule, It was given to me with many faults. It is a Toro con Muchos cuernos, ni siquiera tiene recursos cargados, tiene cerca de 20 open-ends y lags de +300 dias en un proyecto de 5 años. (By the way, please don't leave Planning Planet. Yours is a valuable voice here.)

My conclusion is to slow down, be more patient, ask more and try to reach the pace of the project using P3.

Best regards,

Carlos.

Rafael Davila
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Joined: 1 Mar 2004
Posts: 4780

Carlos,

I would suggest you become the best Primavera user in your Company, then you will get the credibility for them to listen, it will show them is not a matter of not wanting to learn new but outdated products.

I strongly recommend you keep a parallel version of your job in Spider. When in need to reassign crews while Spider will be able to select the most appropriate considering resource leveling Primavera will fall short, here you can showcase the better options using Spider.

 The following steps you can consider:

  1. Import the model into Spider, this I would recommend only once, as transferring between software is never 100%.
  2. Add the unique Spider functionalities that will allow you to model several possible equipment crews, each with different resource composition, some requiring less resources but with lower production rates. Here combinations can become too many, to keep it manageable at the beginning limit the options to consider the most productive requiring more resources and the least productive requiring less resources. Assign higher priorities to the most productive crew (skill). If after resource leveling one of the low productivities crew is selected as to solve issues of resource availability you can look at idle resources and create additional crew/skill, then iterate your model and in a couple of rounds you shall be able to get optimal assignment.
  3. Then temporarily transfer update job files to a Spider Job and update your model by transferring update data to your model that contains all spider functionalities needed for advanced modeling, in this case to model selection of equipment crews using skills productivities. To transfer the performance data from one project version to another open Performance Archive table, in Menu select Table/Import Performance from other project and select the project which performance data shall be used.

Just prove it, if there are no advantages then Spider is not worth it. Those choosing the software might not be at your level of understanding of the capabilities of either software, they just follow the pack.

Until PP forum is improved to the level it was before I will not be as active, no fun anymore. You have my e-mail and you can always contact me directly. There we can talk Spanish so you can forward the communications to your co-workers.

You got to hold the bull by the horns, “al toro hay que cojerlo por los cuernos”.

Best Regards,

Rafael

Carlos,

your project director is right - you shall use the opportunity to learn hydroelectric.

You will be able to apply Spider successfully having deep understanding of the project processes.

The use of Spider Project can be approved only if you will be able to show why its usage can improve project performance (shorter schedule with the same constraints, better simulation of the project performance, costs or whatever that may be considered as huge advantage). You can always transfer Primavera schedule to Spider or Spider schedule to Primavera (in this case some data will be lost because Primavera just has no necessary fields). But you shall start with understanding and modelling the project using any software. Then you will understand if Primavera functionality is sufficient for your needs and if Spider Project will be able to improve project results. You will be able to prove that Spider is worth to use only if you will show that it may help to save money or accelerate the project.

Best Regards,

Vladimir

Carlos Arana
User offline. Last seen 50 weeks 4 days ago. Offline
Joined: 6 Jun 2009
Posts: 178

Thanks Vladimir and rafael,

These posts are really interesting and useful. They are a proof of Spider Project's flexibility when planning. I wish they were in spanish.

Unfortunately (For me) I got scolded by the Project Director for trying to implement another software. Actually, it was a very polite repressal, he told me that any learning should be made as a team and that, although my intents to innovate are subject of admiration, the company is not willing to invest at this time, in new software licenses since "There is no time or budget" to assume that risk and that the client must consent before changing any software.

He also mentioned that my skill using PRIMAVERA is very valuable for the company, and that I should foster that skill while working with the team. I responded that my skill was not to use PRIMAVERA but to build Critical Paths and that skill would be applied using any software, but there are better planning methods and Spider is the tool which better allows them.

Then, he threw a very interesting stone: "You can learn Spider at your home or in your spare time, but here is the only place where you can learn the elements and the way to build an hydroelectric. Think about it as it is a very scarce opportunity. At this time, the important issue is to get familiar with the elements of this hydroelectric in order to be better prepared to plan the next one. I want you to make the planning at that time"

You can see the dilemma here, he made two true affirmations. It is valuable to learn Spider but it is also valuable to seize the opportunity and take the planning for the next hydroelectric. Each president of Mexico builds one as the flag project of his period in the chair. There is one huge hydroelectric each 6 years.

But the effort to maintain this schedule is huge, even using Spider. I can even measure it: The effort to maintain this schedule is so big that at the time when the effort produces a result, this result is obsolete. It is not a problem with the tool but with the approach: Each piece of work has 4 different names depending on the deppartment that is reviewing it. Everybody knows it but nobody wants to change it, specially the client.

And then I have the dilemma, it is hard to me to decide what to do.

I am still young, I still believe in my dreams and want to pursue them, and I know that having Spider I can make the effort to plan and follow them and slowly make my own resources grow. But not everyday you get an offer to plan a huge infrastructure project.

Or, I am not that young and I should choose the rational answer that there will be more money in my pocket if I resist until the next project. In that case, I must find the way to make my effort to create value from here to the next 2 years with my own time as the only secure resource available. Being young in the company, I am in a bad position to claim more resources. There is the need to create value with my effort before requesting additional resources, but I don't know how to create value if the effort with the schedule is bigger than the time available.

It would be very useful a piece of advice.

Best regards,

Carlos.

Rafael Davila
User offline. Last seen 27 min 19 sec ago. Offline
Joined: 1 Mar 2004
Posts: 4780
EarhtWork Sample Job

Carlos,

You can download the files, current job version 1 and baseline version 101.

http://rapidshare.com/files/417827580/EarthWork_Sample_Files.rar.html

As you can see, I added a couple of formula fields to see how much the resource delay and change in activity duration were, if any, after resource leveling. Remember that formulas are, on purpose, not executed automatically, you must select all formulas you want to re-compute and click execute, when in need.

Best Regards,
Rafael
Rafael Davila
User offline. Last seen 27 min 19 sec ago. Offline
Joined: 1 Mar 2004
Posts: 4780
EW Multi-R

Carlos,

I am working on a sample earthwork schedule and it seems multi-resources woks as expected. When an optimal crew cannot be used then next available crew composition will be selected in order of priorities, if available and in your model. The above illustration is a start. Because I am busy this week is not until after Wednesday I will be able to continue.

You can estimate truck productivity per hour equal to:
= (Truck Capacity) X (60 / minutes per round trip)

Sorry, for being repetitive, but remember to convert bank measure to loose measure, on average there is a difference of 20% to 30%.

Best Regards,
Rafael
Rafael Davila
User offline. Last seen 27 min 19 sec ago. Offline
Joined: 1 Mar 2004
Posts: 4780
Carlos,

I forgot to mention that hauling of fill material from different sources usually is deposited on different areas as different sources mean different materials with different Proctor/Modified Proctor curve, this is one of the reasons to suggest keeping hauling and spreading as a separate cycle for every source.

Hauling of unsuitable material shall be treated differently as you can have at the same time hauling from different sources and placing of the material on the same location. The unsuitable material can be spread and chain compacted with shared bulldozers or maybe just one. You can set bulldozer requirements as partial assignment depending on how much each crew can deliver, then if there are enough bulldozers no hauling activity of unsuitable material will be delayed, otherwise the software will delay some hauling and spotting the need of additional resources.

Yes, there is a lot of reasoning behind earthwork scheduling, is mostly about expensive and very limited resource modeling.

Resource Gantt will tell you on any given time how your resources are distributed.

Although I am more into building construction, your posting is quite interesting. Here we have few activities but a lot of resource balancing. Vladimir knowledge on modeling is superb; he is providing clear understanding on the logic of it.

Thanks you both for your postings. Just go on, Vladimir is asking a question already on my mind, what if you got to use less trucks than the capacity of the excavator?

Usually you have a fixed fleet say 12 Trucks, 3 excavators but the ratio of trucks to excavators will vary as the hauling distance varies, here you can define your optimal crew with a higher assignment priority, but because it will not always be available maybe the use of skills with multi-resources as participants can deal with the issue. If the ratio is too low then for such combination you shall not create a multi resource.

Best regards,
Rafael
Carlos,
you can link any number of databases with one project.
Cycle time is used for calculation of the number of trucks that shall be assigned to one excavator. But productivity is usually defined by the excavator. Only if the number of trucks is not sufficient crew productivity is defined by the trucks and in this case productivity is assigned to the trucks. Productivity is truck capacity divided by cycle time.
So first of all you shall decide which resource is driving.
Do you use the same trucks and excavators everywhere or there are trucks and excavators with different capacities?
Carlos Arana
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Joined: 6 Jun 2009
Posts: 178
Thanks Vladimir,
The data gathering has been slow and at this point I think that the schedule that was being used in the project before will work as a base WBS. For many reasons, that schedule is wrong. This is, for more reasons than the ones I already knew when I worked with them.

I got a resource database and a materials dictionary, but I still have problems since there are 3 different databases being used for project controls: the budget, the schedule and the cost accounts. I am dedicated in this point to create a project fragment for a typical concrete colocation, using as the base the resources indicated in the budget. then I will load these to the schedule to show the managers how resources, costs and work can be distributed in time.

This is taking me to learn. Slowly but I am. I feel that i am close to the point of change, everything is very calm in the project, just the way it is before a storm.

Rafael:
Thanks for pointing out the material spreading. Actually, production is measured with placed and compacted material, and the haul productivity is measured with spread materials. In the evening when I get to the building site I will try to model what you have told me.

Also, maybe it is right to consider that the full cicle productivity will include the trip from the placing site to the borrow area.

Best regards,
Carlos.
Rafael Davila
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Joined: 1 Mar 2004
Posts: 4780
Vladimir,

You made it very clear. Perhaps use of skills can be considered as to interchange crews depending on the availability of the Excavator, the equipment that will drive the production. Here your comments will be, as always, welcomed.

Carlos,

Do not forget to include material spreading and compaction equipment as part of the same balanced operation.

An Excel table for your productivities can be handy to have, once you collect the data it will make it easy to assign productivities.

For example:

Productivities for Cut and Fill of Sandy soil using Excavator Type A
************************************************************
Crew 1km haul 2km haul 3km haul
C1
C2.............................CM/HOUR...................................................
C3
************************************************************
C1 = 1ea excavator A, 4ea 20cm trucks, 1ea D6 Bulldozer, 1ea Large Compactor, 1ea Water Truck (20% assignment)
C2 = 1ea excavator A, 5ea 20cm trucks, 1ea D6 Bulldozer, 1ea Large Compactor, 1ea Water Truck (20% assignment)

Although you will generally target for optimal crew production you will not always have all resources available, also at times the optimal solution of the whole is not by optimizing all parts, just because a crew is missing a truck you are not to delay the whole activity. As the job progress, you will have to monitor your resources and make necessary adjustments in crew composition and productivities.

Best Regards,
Rafael
Hi Carlos and Rafael,
there are two tasks. One is very simple, another one is complex.

Easy task - to set material requirements per hour for resource CAT740:
Materials Diesel, Oil, Lot of Tires shall be created in Materials table.
In Resoure table set Material requirements per hour for resource CAT740 - 22.71 liters of Diesel 0.244 liters of Oil, 0.000167 lots of tires.
That’s all. Material requirements will be calculated basing on the scheduled time of CAT740 work.

Another task is difficult. The crew that is involved in mass moving consists of the excavator and trucks. The number of trucks that served one excavator depends on the distance where the mass is moving. It may be 4, 5, 6, depends on the cycle time. So there are different multi-resources that can be used for the same work (with 4, 5, or 6 trucks). These multi-resources shall be assigned to mass moving activities with different distances to the place where the mass will delivered. Crew productivity usually depends on the excavator and so assign productivity (volume per hour) to the excavator.

To be able to use reference-books for multi-resource assignments define different activity types for activities that use different multi-resources.

I hope that understood the task. Inform me if I missed something.

Best Regards,
Vladimir
Rafael Davila
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Joined: 1 Mar 2004
Posts: 4780
5,000,000 m3 is a lot of dirt, adequate planning must follow, and you go to look at how the volumes are spread on the site and decide how to segregate hauling areas into appropriate level of detail.

Here earth modeling software such as Paydirt, Quest, Carlson and the like might help. No doubt a brainstorming session with the superintendents the estimator and scheduler same as for building construction is a basic requirement.

Usually old “Mass Diagrams” are not suitable, too simplified, even if road construction, there is more than a single hauling from A to B, these must be subdivided in appropiate size areas.

ET
Carlos Arana
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Joined: 6 Jun 2009
Posts: 178
Thanks Rafael, it looks like somehow you managed to view the situation in the project. The diagram you made is a typical situation here.

These days when I’ve been reviewing a budget and a schedule for the same project I’ve found that sometimes there are activities scheduled that are not in the budget, or there are budget concepts that are not scheduled. That may be a mistake: What is in the budget should be in the schedule and/or what is in the schedule should be in the budget.

Also, I’ve found that most activities in the budget include material movements. Then, there is still a volume of 5,000,000 m3 of materials to be extracted and placed, so the carriages may not be a minor topic.

By the way, Area 51 does not exist, you should not mention or insinuate that there is an "Area 51" as the government has no knowledge of such place or the activities that supposedly could take place there.

Best regards,
Carlos.
Rafael Davila
User offline. Last seen 27 min 19 sec ago. Offline
Joined: 1 Mar 2004
Posts: 4780
Earthworks


We can talk about modeling of material resources production and compsumpion as it can also be modeled but if not relevant to schedule logic I would not get into this much detail. Remember at the time of updating your network too much detail might backfire.

Maybe my fragment would consist of a single hauling activity, still very useful to transfer among jobs (or within a single job) the resource and the crew productivities at a single click instead of breaking my mind using Excel, I would even avoid using the more powerful reference books. It is about being practical.
Carlos Arana
User offline. Last seen 50 weeks 4 days ago. Offline
Joined: 6 Jun 2009
Posts: 178
MM ... somehow my first post was messed and I can’t edit it now. here’s it again:

Good day, I want to model a typical work fragment for material carriage. In the project, we use cat 740 articulated trucks for carriages:


The CAT740 consumes oil, diesel and tires. It also has its own operator. I modeled a multicrew wich uses the CAT740 and an operator for CAT740.

Now, what I don’t know how to add into the model is the Diesel, oil and tire usage. From the budget I got the following data:

1 hour of articulated dump truck usage consumes:
22.71 liters of Diesel
0.244 liters of Oil for diesel engines
0.000167 lots of tires (A lot of tires includes the 6 tires)

And from the Caterpillar Performance Handbook I got the following data:
Top speed: 54.7 km/h
Max capacity (Should not be exceeded): 39.5 Ton; 18.5 m3 (struck); 24 m3 (Heaped 2:1)

The carriage time from each material center to each placing site will vary depending on road lenght, but how do I model the carriage inside Spider? Or is this an excesive level of detail? Then, how can I model the material carriages?
Carlos Arana
User offline. Last seen 50 weeks 4 days ago. Offline
Joined: 6 Jun 2009
Posts: 178
What I don’t get is how to make the fragment flexible so that it can be used if the type of material will be different, or if the lenght of the road from material bank to placement site will vary or if the total volume to be carried will vary.