P6 Calendar changes during the project

Installation of Materials are consumable resources that represent volume of work, if used on same activity they represent different volumes of work on same activity. Same as regular renewable resources they must be leveled, if not available activity execution stops. Because their installation is a function of brick installation it is enough to model Bricks volume of work for activity, you shall be able to view materials installation/consumption within a view or a report. Now we are talking about models a tad less easy. A detailed discussion of this belongs to different topic.

In this scenario materials are to be delivered once a week by barge to a remote island.

Apologies to A. T. who started this thread, I just hope you enjoy the discussions (I like Rafael's background music). Vladimir said: "Activities with different volume units and assigned resources shall be shown and calculated separately in the detailed schedule". While Rafael said: "Once you got a good model, automatic resource leveling comes at a single click, a piece of cake". Well, I cannot agree more, but I guess P6 can always do the same (as exactly based from your own statements that I quoted). 

So perhaps it again boils down to how detailed a schedule need to be to arrive to the best model where you can do resource leveling at a single click. In other words, if your schedule (or activities) is not discretely measurable, then it is not a good model, therefore when applied with automatic resource leveling, may always come out with eroneous results. 

The thing is: When you are working with a multi-disciplined, multi-contractor and or multi- specialty subs, then how can you create a good modeled overall schedule?

From real life experience for example: In High Rise Building construction, they normally use 1st Fix, 2nd Fix, Final Fix as activities for Electro-Mechanical works, so of course these are not applicable, but these are what management wanted to see.

In Oil & Gas plants, you may use Inch-Dia or Inch-Meter for piping works which a bit measurable (but very confusing sometimes), however, fabrication of piping spools, vessels etc. maybe done in another continent so how can a poor Scheduler on site create a good model for a schedule? 

In shutdowns / Turnarounds, how do you measure activities like degassing, pigging, putting spirits or detergent, gaskets, blindings etc. etc. etc. and apply automatic resource leveling? 

Once you get a good model automatic resource leveling comes at a single click, a piece of cake. Creating models for different shifts on same activity is usually a piece of cake if using Spider Project. I expect it to be the same if using P6. Needless to say that more complex scenario can be difficult but my sample scenario is easy, it is about a single activity, cannot be any easier.

As I see it, it is just a matter of learning how to use the software.

If not that easy, that is fine, what is not acceptable is that you cannot model different shifts on same activity and get reliable results without using manual adjustments. Artificial splitting of activities is wrong, no matter the purpose.

Fair enough for me. Thanks Gentlemen. However, I for one believe that even a single unit of scope may need to be separated depending on crew, equipment, price and sequence necessary. For example: Rebars or steel reinforcement maybe measured in terms of kilograms (kg), and Formworks maybe measured in terms of square meters (m2) and Concrete is in cubic meters (m3), and they all boils down to cubic meters or volume of concrete. What I'm trying to say is that: even rebars and form works have their own unique unit of measures and perhaps prices, they may need to be separated within themselves. Why? Again, for example: There maybe completely separate activities involving exactly the same material, and may as well utilized completely different equipment. Another Example: Fabrication (maybe in shop or on site), and Installation of course on site. And you don't only bite these materials but of course you use some kind of equipment in order to utilize them and serve its purpose. So who's saying that automatic resource leveling is a piece of cake? Come on, please show us some realistic thing and not just an imaginary activity (which maybe manipulated).

The following video showcases how artificial splitting of activities can yield undesired results.

• If Activity 1 is split but its execution shall be contiguous depending on resource demand and availability resource leveling might or might not schedule undesired non-contiguous execution of sub-activities. If you add resources A then it might schedule contiguous execution of sub-activities.
• It might be that initially sub-activities are scheduled contiguous but if delayed they might be scheduled non-contiguous. The might or might-not must be eliminated in order to get a good model, you eliminate it by avoiding artificial splits.

Artificial splitting of activities is not a good practice, unfortunately there are many who promote the contrary by requiring all activities to meet some maximum arbitrary duration, the workaround being artificial splitting.

 

Anoon,

on the screen below one activity that is done in three shifts.

On the 1st day only shift 1 is available, on the day 2 shifts 1 and 2 are available, on the day 3 all shifts are available.

Activity has 100 units volume. Productivity of the first shift is 1 unit per hour, second shift has 0.9 units/hour and 3rd shift 0.8 units/hour productivity. They work until the whole activity volume will be done.

Let's assume that they spend some material with the name of concrete 1 unit per volume unit.

Diagrams below Gantt Chart show material consumption per hour and cumulative.

I don't know if understood you question properly. And I agree with Rafael that activities with different volume units (and assigned resources) shall be shown and calculated separately in the detailed schedule.

The example I provided is for a single unit of work that drives the activity duration.  If there is another unit of work that drives activity duration in such case their volumes of work are not incidental but independent, if two independent volumes of work it makes two activities and merging the two into a single activity will be as wrong as splitting the activity in my example.

Anoon,

Same as Vladimir I cannot follow your request but It is enough to show the one activity sample schedule I already provided. It is a no brainer, if activity start moves so do shifts start, because shifts have different production rates the activity duration changes. If you split the model into two activities in no way the model will make the adjustments as it will not know what volume of work is to be performed by each individual activity. If the volume of work is kept within a single activity the volume of work remains 500cm. Please turn on the volume, the music is on the house, expand to full screen for a better view.  

Please take a look at my Fri, 2018-11-02 18:43 post for a static view.

If activity starts on Monday:

Monday =>> Resource 1 will produce 100 cm

Tuesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 2 will produce 150 cm

Thursday =>> Resource 2 will produce 50 cm in about 3 hours

Activity will take 3 days 3 hours.

If activity starts on Wednesday :

Wednesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 2 will produce 150 cm

Thursday =>> Resource 2 will produce 150 cm

Friday =>> Resource 2 will produce 100 cm in 6.67 hours

Activity will take 2 days 6.67 hours.

After all work is done no need for resources to hang around doing nothing, they will be realeased and become available to do work on other activities.

Best Regards,

Rafael

Ok, maybe not fair enough, but that's real life anyway :). In my opinion what Rafael is saying "Maybe" or only applicable to single unit of scope, but not for activities involving multiple units of scope like concreting for example. Please confirm Rafael, come on! Be fair.

There is no problem Vladimir. I'm just quoting Rafael who said: It doesn't make sense to break up an activity involving multiple crews and or shifts as it may result to erroneous automatic resource leveling. As I believe Rafael always have a better way (if not the best) to do scheduling. So if you may kindly please show planning planet community if how you actually do it in real construction activity like for example: Concrete Foundation. Without breaking up or granulating the said activity, please show us how you assign multiple crew and shifts and arrive to a realistic schedule (in your simplest and quickest way and of course, accurately). Many thanks in advance.

Hi Anoon,

I don't understand what is the problem to be solved.

Please explain suggesting the detailed example.

For real life example: Firstly, you got a simple activity called Concrete Foundation. One activity, resource loaded with several crew and shifts for example. This is a challenge to Rafael and perhaps Vladimir (though I got nothing to bet). Please show us how you schedule it correctly using automatic resource leveling. And please explain further on how you have considered components such as the following: Earthworks, Formworks, Rebars, and Concrete. Simple as it is and may make people's belief changed in an instant perhaps.

Breaking up activities does not make sense when different teams work on the same activity.  Splitting the activity is a very poor work around when different shifts work on same activity.

When you split a resource loaded activity because other activities might be competing for the same resouces there is a risk each sub-activity will be scheduled non-contiguous by the resource leveling engine.  If not enough re-distributing the volume of work among the sub-activities and calculating their adjusted durations every time these are delayed as schedule moves will be a nightmare.

Learn to schedule shifts within same activity using your software, no big deal, should be easy.

Question no. 1: Yes of course as you introduce new resources, correspondingly, adjustments to the schedule and or calendars would be necessary. You might consider breaking up some activities while shortening durations and accommodating several shifts.

Question no. 2: Additional workforce or resources would mean additional cost. However, Time also means cost. So I guess it is just a matter of balance between time and cost. Which one is economical without sacrificing quality and the committed completion of works.

1) If you are working on a project which starts with only a day shift then so far into the project a night shift is introduced, do you need to reflect this night shift work in the calendar? 

not necessararily it depends if you are tacking and manloading the schedule. A working day is still a day no matter if it is 1 or 4 shifts it how you want to represent it. 

2) What difference does it make to the schedule if you change the calendar apart from changing the activity durations? 

it depends on wht changes you make to the calendar. For example if you add holidays that reduces the available number of working days for that particualr month. Thus reducing the available overall time frame for the project. 

1. you may create a seasonal calendar maybe you can only plant during the fall and spring. Then you assign planting activities to this specific calendar which means that the planting activities can only happen in the spring and fall window.

2. Maybe your job shuts down during the winter. Then you would block out the winter months in the calendar. That means that now work will be shown during the winter months. 

3. Maybe you project closes from Christmas until after the new years. That means no work will be shown during this period. 

bottom line it all effects the calacualtion of total float. 

Be reminded that usually work on different shifts is scheduled at different hours per day, using different crew with different production rates.  I do not know how P6 deals with such scenarios but the need to model team assignments and independent assignments is essential to model shifts on same activity.