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Using Resource Curves ?

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Ronnie Campbell
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Firstly can I just say that I am a not greatly experienced P6 user and this might be something fairly simple I am doing wrong.

Here goes - Can anyone suggest how I best achieve my desired report or view? To explain - I have a number of future projects that currently only have Level 3 WBS with a few high level activities added. At this time these projects are held in the PMDB and are really only used as placeholders for future work. Each of the Activities at Level 3 are representations of the various phases the project will be required to pass through. The particular phase I am discussing is the ‘Construction’ Phase. Some projects will be deemed as being no longer viable and be deleted but some go ahead will be developed into full blown programme schedules at some stage in the future. In order to give an indication of future labour resource requirements I have created (or will) an activity and make it a ‘WBS Summary’ in each of the projects just below the Level 1 WBS. There are some 50+ of these projects in the portfolio. No two of project durations are the same and range anywhere from 6 months to 4 years. However they do all use a fairly standard set of Labour Resources. For this example I'll use the Civil Engineer Resource or Role.

In preparation what I have done so far is to gather the % of the Civil Engineer’s time spent on historical projects by month. I have 6 sets of data from these completed projects. Ideally I wanted to get an average time by month a Civil Engineer spent across these 6 projects. However as they were all varying durations, some have 6 months and others have 12, 18 months etc. So it was difficult to get an average by month. I thought using the 'Create Resource Curve' in P6 was the way forward. For example where a historical project had an overall duration of only 12 months I interpolated the 12 values to create 21 data points and represented them as % of the engineers time. Similarly for a 6 month project I interpolated to get the 21 data points. In short the end result was that at 5% of the project duration the Engineer was spending 27% of his time for eaxmple, by 40% he was spending 35% and so on. By creating a common denominator if you like of 21 points I was able to total and get an average from the 6 historical projects. This gave me in Excel a Profile of the engineer's time at 21 points across the 0%-100% of the project duration. I should say at this point that I am aware of the limitations and the level of accuracy this approach is likely to give but it is only intended to be a rough cut at this time for the guys at the top of the totem pole. As a project gets the green light it will be expanded in detail and resource loaded in the normal way.

So, armed with 21 average data points for a Civil Engineer I then tested the approach on 4 projects. I created them such that they all had varying duration WBS summaries. My thinking was that as the curve X axis was 0% - 100% then the duration wouldn't matter as the resource requirement would be shown by month be it 6 month or 24 months. I had hoped that by then opening all 4 of the test projects simultaneously each with the Civil Engineer assigned to the Summary WBS and each with the newly created Resource Curve (Civil Eng Profile) I would get a picture , screenshot or be able to create a report that tells me my Civil Engineer requirement is OK or if I have an over allocation at some stage across all 4 projects. What seems to happen in P6 is the Resource Curve for the Civil Engineer is quite happy to allow an over allocation. I have tried various different changes in Duration Type , Tried changing the ‘Remaining Units / Time % (or Xd/d) In summary what I want to achieve is to be able to see my resource requirement by month across all four projects (prior to rolling it out across all 50 ) . I need to see my over allocation in any given month and I need to repeat this for the entire set of resources - Electrical Engineer, SCADA engineer etc etc. It's not an option to use the normal bottoms up approach of allocating resources to a 'Task Dependant' activity as these have not been fully added to all 50 programmes at this time. If anyone has a solution or any ideas I would welcome any input.

Thanks & Regards

RC

Replies

Khuong Do
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Hi,

I wrote an article regarding How does “Resource curve” work?

If you're interested, kindly read it here https://doduykhuong.wordpress.com/2016/01/09/how-does-resource-curve-work/

Cheer

Ronnie Campbell
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Thanks guys for the replies. I'll give it a go.

Regards

Ronnie

Shareef Abdul Azeez
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This can be made a lot more complex 

If we all try

 

Thanx

Rafael Davila
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Ronnie,

Christopher method should do the trick and is simple until you start updating the schedule and different activities actual happen in the middle of the individual curve, each at a different point, this slightly complicates the issue, especially when you switch to named resources and use the schedule to manage your manpower. 

You can apply this method to not started jobs and as soon as the job is committed and scheduled use bottom up scheduling with a sufficiently detailed breakdown that does not require the use of resource curves. This will make it easier. 

Most probably this method is documented on P6 literature as it goes to the bare bones of how resource curves are implemented.

I probably would  add the 21 workload values and divide by 21, this will yield the average daily workload and multiply by calendar average hours per day to get the scale factor for 1 resource 1 day. Then total mh can be computed by multiplying the scale factor by activity duration in days by resource quantity. 

Best regards,

Rafael

Christopher Hall
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Ronnie, seems simple enough.  "Variable units/ time" defined by a given curve based upon duration % applied to a variable duration.  The issue is the variable duration and how P6 overallocates when using curves for 1 unit/time with a limit of 1 which i presume is what your implying.

There's probibly easier ways in P6 but here's how I'ld set it up;

  • define curve in P6 (your 21 points), think percentage of the unit i.e. 27% of 1 civil engineer.
  • create a spreadsheet, in your instance with 50 row items for each variable duration activity (WBS summary / LOE), duplicate for multiple resources.
  • imput your 21 data points from the curve, the current duration and your limit (100% = 1 engineer i.e. 8h/d) for each variable duration activity,
  • use excel to intergarate the area under curve defined by the said duration (X axis) & percentage of resource used i.e. 27% of 1 civil engineer on a given day/week/month in hours (Y axis)
  • the area under the curve gives you budgeted hours to apply to the activity over the activity duration, the defining variable in this instance
  • import/ imput budgeted hours into P6 for that resource,
  • apply curve and your done.
  • use tracking/ historgram to determine & present overallocation based upon choosen limit for that resource.
  • You could go further by presenting in a stacked histogram based on resource project allocation to determine what project/s at any given time are resulting in an overallocation.

If your updating, statussing & scheduling the project/s i.e. varying the durations, you'll need to iterate throught the above process each time you report/ audit this style of resource assignment.  Can't imagine it'ld take more than 10 mins each time if you set it up right.

Rafael Davila
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Photobucket

This is an issue of fixed resource quantity with variable workload, perhaps variable units/time in P6 language. You might be switching workload and resource quantity and they are not the same. You got it when you tried with remaining units/time just that you cannot apply a curve to this parameter as you can to resource quantity. It is a very simple allocation for which I used special fields to determine the duration of the different phases for each job. I defined a "phase" for each workload discrete duration. I defined the resource as non leveling because I do not want it to drive the activities during resource leveling. If there is an overload then I would fix the supply.

From the above figure you will see that during Oct and Nov 2 resources A will be needed.

After you get it we can start talking about how with the use of skills functionality you can see the details on how each individual resource unit is assigned and how to keep some control using priorities and in some cases using direct resource assignment instead of only skills with or w/o priorities.

It is different software but the general concept shall be similar.

By the way I do not believe P6 resource level those resources to which a curve has been applied. Maybe old P3 but at the cost of a poor resource leveling algorithm that would use some kind of "brute force".

Best regards,

Rafael