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Full Time Equivalent

4 replies [Last post]
David Kelly
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630

Some time ago I was involved in the beginnings of a discussion here about “Full Time Equivalent” (FTE) with Vladimir and Rafael. I thought I would “complete” my thinking about this.

P6 is basically unequipped for this, and we have to fudge it.

I live in a world where the scope of work estimate is always in manhours. These are almost always what our American cousins call Wrench Time. No meal breaks, no permit delays, no walk-to-work.

Contractors have sophisticated Work Management Systems (WMS) that have norm based estimating systems within them that create a manhour content that is NOT FTE compliant, e.g. what does 47.45hrs of Pipefitter, and 17.32 hours of Rigging actually mean in terms of number of men on the job? I have never encountered an estimating system in my Oil, Nuclear, Defense, Ship Building, or Renewable worlds that tells me “how many men”.

For forty years what we have done next is to impose a methodology that helps us understand the impact of non productive time. We do not have “resource efficiency” or anything like it in P6 – so we either:

 

  1. Reduce resource availability (e.g. I’ve got 6 electricians, so I will tell P6 I have 4)

  2. Factor the manhours (e.g. this job is at the flare tip, needs three permits, a LONG climb to work – lets multiply the manhours by 3)

  3. Reduce the number of working periods in the scheduling calendar. (e.g. We are paying for 12 hours, but on a satellite platform we only get 4 working hours per day.)

Option 3 is universal as it preserves the manhour content in the estimate which option 2 makes irreconcilable, and does not increase my FTE algebra as option 1 would.

So I am left with Wrench Time and an activity calendar that seeks to match CPI. Dividing one by the other to approximate FTE is the best we have got. Yes, we could ask the maintenance manager to code some FTE information on the 25,000 PMRs he has per asset, but he would probably just ask us to change our medication. The obsession with CPI in my wholly reimbursable world makes it the commercial divisor of choice.

There has been a breakthrough for the asset owners in the FTE debate. The asset owners I do most of my work for are the operators of offshore oil and gas installations. Having more men on the platform than there are beds (strictly speaking, seats in the emergency escape vessels) is illegal. The common logistics package which monitors all movements of personnel, helicopter flights, crew rotas only knows about number of men. We must have exactly a full complement of men on board at all times. Dividing P6’s manhours by anything is no way to meet the statutory obligations. The interface between P6 and the Vantage logistics system has been a tortuous path through exquisitely complex spreadsheets.

Let us take a worse case example from Vladimir’s complaint about FTE. We have to send a specialist offshore to do a job estimated at 4 manhours. We need a flight out and a flight back and a bed for all the time he is there. Only the logistics system knows the flight dates and hence the duration of the activity. We now have an integration program between the two systems (logistics and scheduling) that allows someone using the P6 Window’s client to send a request for an offshore visit directly to the queue of the logistics system, and when successful it writes back the date of the fights in and out – and a new resource assignment “Bed” for every day the specialist is offshore to do the 4 hour job. If our specialist’s return flight is delayed, then the Actual FTE is more than the Budget FTE. This is effectively “double dipping” the work to create 2 resources – 4hrs of “visiting specialist” and 4 days of “bed” on the same activity.

The bit I like most is when the crew swipe through the heli-deck with their ID cards, the Resource Availability in P6 is updated to reflect exactly those personnel on the platform.

This means all of the really difficult FTE sums are done in the logistics system, and the results written to P6. P6 behaves perfectly well with this data – I would just HATE to have to type it into the Resource Assignment table myself.

 

So P6 can work with manhours and the difficult relationship with number of men. It just needs some help with the maths. P6 is light on estimate-and-approval, and I put “The Valdimir problem” in that category.

 

Now whether this whole issue is for “scheduling” software to fix or “estimating” or "logistics" software is a rant for another time…….

 

 

 

 

 

 

Replies

David Kelly
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630

Thanks for the feedback guys.  I am very comfortable with the P6 FTE workaround that we have - do it in another system! It is working very well at several clients.  Of course it all adds to the fun of resource levelling. 

About forty (gasp!) years ago when I was young enough to do the maths, I set about designing a resource levelling program, as I was unhappy about not being able to prioritise the resources for closeness of fit to the availability in the tools that were available at the time. I was keen to always prioritise beds as the resource that must be fitted to the availability curve even at the expense of individual trades. I remember almost nothing of it now! I extended a fairly conventional minimum moment matrix algebra "solution" (we didn't know it was NP then!) and it seemed to work pretty well. I do remember one line of code had fourteen pairs of parenthises. Then the mini-computer supplier changed the compiler and some of the matrix algebra instructions I depended on were dropped..... a very expensive lesson! I have used off the shelf tools since. 

David Kelly
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630

Thanks for the feedback guys.  I am very comfortable with the P6 FTE workaround that we have - do it in another system! It is working very well at several clients.  Of course it all adds to the fun of resource levelling. 

About forty (gasp!) years ago when I was young enough to do the maths, I set about designing a resource levelling program, as I was unhappy about not being able to prioritise the resources for closeness of fit to the availability in the tools that were available at the time. I was keen to always prioritise beds as the resource that must be fitted to the availability curve even at the expense of individual trades. I remember almost nothing of it now! I extended a fairly conventional minimum moment matrix algebra "solution" (we didn't know it was NP then!) and it seemed to work pretty well. I do remember one line of code had fourteen pairs of parenthises. Then the mini-computer supplier changed the compiler and some of the matrix algebra instructions I depended on were dropped..... a very expensive lesson! I have used off the shelf tools since. 

Rafael Davila
User offline. Last seen 10 hours 19 min ago. Offline
Joined: 1 Mar 2004
Posts: 5229

Be reminded that Beds in an offshore plartform are Spatial Resources,  so easy to level if modeling creation and consumption consumable resources.  If there are not enough beds then some activities that require the spatial resource must be delayed until released, elementary, a no brainer, so basic a single click shall do it.

Resource types

  • Go to slide 3 for Resource Quantity.
  • Go to slide 7 for an example of how leveling based on available man-hours may be wrong if resources are assigned part time.
  • Go to slide 37 for Spatial Resource modeling.

Enhanced Resource Planning from Rafael Davila

Best Regards.

Rafael

David, man-hours are used by estimators because they calculate costs basing on production norms.

For them it does not matter if some job is done by two persons in 2 hours or by one person in 4 hours - the cost is the same.

But managers need to know resource quantities required to do the job. And estimated manhours and quantities are not proportinal because some resources are used part time. So there is a need to know both resource quantity and workload required on each activity. Knowing both we will be able to calculate the schedule and efficient man-hours and resource idle time.

Managing projects we always need to manage resource quantities and minimize idle time optimizing resource constrained schedules. With poor schedule the project duration is longer though "efficient" man-hours are the same.

Planning activity execution we shall know the volume of work to be done, what crew shall do the job, what is crew productivity.

Crew productivity is determined by the productivity of the driving resources but the crew uses also facilitating resources that do not always work with the full workload but still needed. If possible these facilitating resources may work with the several crews in parallel (part time with each). Examples: tower crane, helpers, etc., depends on the type of work. But these facilitating resources may be critical (drum resources if to use Critical Chain terminology) like the cranes in building construction and so planning their part time assignments is necessary for optimizing resource pool and project schedule.

Determining the number of beds is an example when knowing resource quantity is critical but in any case and in any project this information is required.

Another example usual in my practice - planning pipeline construction at the remote area. We need to plan the quantities of pipelayers, bulldozers, excavators, welders, etc. that shal be moved to the construction site. Not all machines and people will be used for 100% of their work time and this is inevitable for many reasons. And total man-hours and machine-hours is not reliable information for planning resource quantities.

And of course available resource quantities (not man-hours) is initial information for calculating project resource constrained schedules.

At the platform some specialists are required but do not have enough work to do to be busy 8 hours per day.

And resource leveling based on available man-hours may be wrong if resources are assigned part time.