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# quick and Rough calculation of Manpower required

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abdul raheem moha...
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Joined: 20 Nov 2007
Posts: 12

Hi all
Thanks for the cooperation that planning planet community shows

Is there any method to arrive at total manpower reqiered to finish a project with a break down for mason steel fixer and carpenters

I try to solve an example shown below, please correct me if I am wrong????

3 basement + ground + mezzanine floor + 20 typical floor + roof
Basement has 2000 m2 area and each typical floor has 1000 m2

1: calculate total man power required?

Total Area =3x2000+2000+2000+20x1000+1000= 31,000 m2
Total manpower required for completion of project with I shift working daily = 31,000 X 8 = 248,000 man days
( please correct me and Show the thumb rule)

2: peak of the project ?
Average =248,000/24/30 = 344 nos
Peak = 1.95 X 344 = 670 nos at peak

3: each trade percentage of contribution say (Steel fixer+ helper) 32% of peak, (carpenters + helpers) 30 % of peak and reaming (masons + helper ) 38 %
Steel fixer + helpers = 32 %X 670 = 214 nos
carpenters + helpers = 30 %X 670 = 210 nos
masons + helper ) = 38 % X 670 = 254 numbers

All together if you know the thumb rule to calculate please guide, without going into details of each activities which could be 5000…!!!
Do tell me what is the restrains of labour working in an area? I what is the maximum no that can work in an area.??

Best Regards

## Replies

Mansoor Ali
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Joined: 29 Jan 2015
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Mr. Abdul Raheem,

Can yo please tell me what is 1.95 in your calculation and how it comes?

thanks

Siddic K
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Joined: 11 Oct 2011
Posts: 6
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Hi Mr.Mike,

Thanks for your reply. But usually we are having 2 stgaes in bidding, 1st We have to submit technical, if it is passed then they will instruct us to proceed for Commercial submission.

So, as you said i could't get tender contract value.

In this case how to estimate the manpower and equipment..?

Thank very much

regards

Siddic K

mike mm
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Joined: 22 Jun 2014
Posts: 2

During the tendering stage, the quantity surveyor prepares this LMES. This are the  Labor, Materials, Equipment, Subcon.

All of this comes from the Unit Price Analysis. This UPA are based in the productivity rate.

Mike Testro
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Joined: 14 Dec 2005
Posts: 4100

Hi Siddic

Take the tender price and extract the Resource hours.

Have a guess at the averege resource deployment - calculate a rough duration.

Best regards

Mike Testro

Siddic K
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Joined: 11 Oct 2011
Posts: 6
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How to calculate the manpower & duration in tendering stage....???

is have any thumb rule.....?

regards

Siddic

Ruel Camaquin
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Joined: 16 Nov 2008
Posts: 87
Guys,

Correct me if i am wrong... but here’s the way i understand manpower requirement & scheduling, in steps:

1. Quantity / Production rate = Total Manhours (to get total hours to be consumed)

2. Total Manhours / 8 hrs = Total Mandays (to get total of days for work to be done)

and

3. Total Mandays / Desired no. of skilled crew = No. of Workers (to get the desired no. of days for a work to be Done)

example:

100.00 sqm (qty) of raised floor / (2.60 sqm/hr) PR = 38.46 mh/ (8 hr work/day) = 4.81 mandays / 2 (desired no. of workers) = 2.40 days

or say; for a 100 sqm of raised flooring installation i will be needing 2 skilled worker and work duration will be just 2 day.

Steps 1 & 2 has a fixed value for qty, production rate & work/day, only the value for the desired no. of workers will be determined by the planner or scheduler if he/she wants the duration longer or shorter.

Thanks.
Roland Tannous
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Joined: 15 Oct 2009
Posts: 84
Groups: GPC Lebanon
Did I just read 214 steel fixers and 210 carpenters for a maximum floor area of 2000 m2 at a time?
Did you mean at a time?????

I am not surprised at all!
Ever heard of trade stacking? Productivity loss with increased numbers? labour per m2? Optimum Crew Sizes????Tower Cranes? Tower Crane capacity? Logistical constraints in General?????

I am not surprised to see what you wrote knowing where you’re coming from. This is a concept that people use blindly round here(Middle East, Gulf, call it whatever you want)to approximate manpower with no consideration whatsoever to the parameters of a project, to productivity in general or capacity.
They think that the more labourers they throw in the faster they will be...

For the project you just mentioned I’d be even able to get to third of the manpower you mentioned and still finish on time..
Now I wonder why contractors round here barely make any money.
abdul raheem moha...
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Joined: 20 Nov 2007
Posts: 12

1)This example of "3 basement + ground + mezzanine floor + 20 typical floor + roof" was put me in a short interview. where budget of the building was not provided. and this was to be solved in five minutes. total Built Up Area is 31000 m2

2)with previous experience if i divide "total area" by "total labour consumed "man days (10 hrs)" " then figure comes to "7 or 8 man days per square meter" approximately for industrial building . this no could differ based on production rate i considered average production rate

3) ie if i multiply 7 0r 8 with "total building area" i get approx cumulative labour needed for completion of project.??

Mike Testro
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Joined: 14 Dec 2005
Posts: 4100
Hi Abdul

You have to relate your resource levels to the cost plan which will show you the remaining values of the several trades involved.

Take each trade total and remove the OH&P.

Apply a reasonable percentage that represents the labour content of the value to get to the labour value.

Divide the labour value by the average rate per hour for each trade and you will get the total labour hours - divide this by the hours in the working day and you will get the number of resource days.

These days can be allocated pro rata to the activity durations and the calculation balanced by a reasonable gang size.

Best regards

Mike Testro

abdul raheem moha...
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Joined: 20 Nov 2007
Posts: 12
Hi all
your reply will be highly appreciated. Do consider calculation of manpower requirement at Tender stage, where i will not go into details.Though such calculations comes with experience, but i love to hear some one who can put this calculation in mathematical format