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Estimating Total Construction Manpower

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Richard Beazley
User offline. Last seen 11 weeks 8 hours ago. Offline
Anyone out there who can give me some guidance? I’v only been a planner for 30 years and I’m still learning !!
We have a "Mega Project" here in Thailand - 7 major petrochem projects on one site ! Very early stages, like almost nothing has been designed yet, but we do know the planned output of end products, and a rough schedule.
We are trying to establish the size of the total workforce at peak. i.e. in simple terms, how big a camp should we build? catering.... buses..... ambulances... high level planning. It will be a whole lot easier when we get more information, but for now are there any guidelines out there?
Our current estimate is between 3000 and 8000, but that’s too broad !!
your ideas are welcome !


John Lawson
User offline. Last seen 3 years 36 weeks ago. Offline
Joined: 6 Oct 2004
Posts: 113
Hi Richard

Interesting problem you have there!

As your project is not even at the "questimate stage" any number chucked into the ring is as good as the next.

At at this stage of the work, your two educated quesses are the best you can do untill you can get some lower level estimating/costing organised.

Try basing the camp size and its services on an average of your two numbers, spread out equally over all the projects, then as the estimates develope update your original number. Its the best that can be achieved at this stage of the project.

But at the same make sure the layout and area of the camp / services can be easily changed modified to reflect increases / degreases in numbers etc.

It never ceases to amaze once we planners have "developed" a number, others will start to produce their numbers and so the estimate will clarify etc, but make sure your management understand what your numbers are based on and how they have been developed:- (its called diping hands in the blood).


John L.

Richard Beazley
User offline. Last seen 11 weeks 8 hours ago. Offline
Hi Oliver,
Appreciate your quick response! And you are absolutely right. The reality is that we are the Project Management Contractors/Consultants. The client, who has all the estimators, cost engineers etc have given us no information at all, though we do have rough figures for total budget.
They have no plans to give us the schedule because it is not firm enough to plan with...!! Again we have a very rough one page schedule, which has been overtaken by events. Each of the projects has a completely different sponsor, financing arrangements etc. It’s going to be challenging to say the least! They are working on estimates and the minute I have those I can work it out!
I guess I need to search our archives and dig out data from similar projects. my email is richard_beazley@fwuk.fwc.com if you want to engage in more discussion.
Oliver Melling
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Joined: 24 Apr 2007
Posts: 595
Groups: The GrapeVine
If you have a rough schedule, then compare the project to similar jobs completed in the past and do a ’top-down’ estimate.

If you think it is going to cost around £50 million, then apportion the budget to the ’end products’ and divide the budget between the different resource disciplines/expenses/P&E that you’re going to employ/procure etc. (Don’t forget to escalate the costs in-line with inflation)

Divide the resource budgets by an assumed rate of pay and then you will have budgeted man-hours. Profile this against your rough schedule and you will get a resource profile to base your camp size upon.

One question, surely a ’Mega Project’ should have estimators or cost engineers?