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Manhours as resource

7 replies [Last post]
Rajkamal Tangirala
User offline. Last seen 24 weeks 1 day ago. Offline
Joined: 29 Mar 2010
Posts: 9

Hi,

We have a sub-con who has loaded Manhours as a resource for all the Disciplines and related activities. As per contract client has specified that 260mhrs/month need to be considered as basis for planning. On this basis they have extracted from P6 manhours budgeted per month divided by 260 manhours to get the manpower required for the month. But they are activities where the resource utilization is only .35days and so. please refer the link. Should i agree with them or go to each activty get the activity duration based on the calender and then divide the manhours-budgeted by the duration to get the manpower requirements. 

Kindly guide me.

https://app.box.com/s/ew5xqzt5sgm4qsul27p1

 

Br-

rajkamal

Replies

Hany Edrees
User offline. Last seen 9 years 33 weeks ago. Offline
Joined: 6 Oct 2008
Posts: 7

Rajkamal,

I changed the function but didn't make any difference because you didn't use the duration in your calculation nor the sub-contractor.

My understanding is that manpower figures in such excel sheets is an average for the whole month ... I didn't say that you are wrong but if I see manpower figure=19 under April  I'll understand that over the whole month we will have average 19 workers for that activity  which means 19*260= 4940 MHr and I will not know that you mean this 19 workers are only for 13 days of April.

while in the sub-contractor calculation this number will be almost 10 which is close to reality even if not very precise and not assigned to certain duration in April.

Check the difference in  whole April :

Your calculation : 55 Workers * 260 = 14,300 Mhrs

Sub-Con Calculation : 38 Workers * 260 = 9880 Mhrs (which equal to the 9823 Budgeted manhours from P6 if we ignored the rounding of figures)

 

This is my understanding and please anybody can correct me if it is wrong

Thanks

Rajkamal Tangirala
User offline. Last seen 24 weeks 1 day ago. Offline
Joined: 29 Mar 2010
Posts: 9

Hi Mike/Leonardo,

Thanks for the suggestion.

I agree with you guys the Days shall be 26 working in a month only fridays are Off. 

I shall consider your advices. Kindly provide your view on my post.

Hi Hany,

Thanks for replying.

That's right about the calculations the upper one from the Sub contractor and the lower one i have prepared it. 

I agree with you, that i considered all the days in month in order to just have a tentative figure the Variation between the contractor's and mine having a difference of 100 at some time.

If you look at the Column H in the Spread sheet i have a formulae to calculate the Network days. You can replace "7" by "16".

Now based on the revision for ex.  activity duration for Activity ID " C-AC-ST-10 " is  13 days having a budgeted hours of 2506  lets consider in order to complete the 2506 hrs in 13 days @10 hrs per person the manpower required would be ~19 Nos.

This can be done for the Whole project. The resources are derived from the activities then cummulated for the whole project. This is my understanding correct me if am wrong.

 

BR-

rajkamal

Hany Edrees
User offline. Last seen 9 years 33 weeks ago. Offline
Joined: 6 Oct 2008
Posts: 7

Rajkamal,

I had a look on your excel sheet, What I understand is that the upper calculation is your sub-contractor calculation (e.g. Manpower for Apr. 2014 are 38 persons) and the lower calculation is yours (e.g Manpower for Apr. 2014 are 55 persons) .. Is this right?!

If so I think your sub-contractor manpower calculation is correct and you made two mistakes in your calculation :

1 - You ignored the activity duration and counted all calendar days including Friday which is day-off !

2 - You and your sub-contractor use different approch .. While your sub-contractor is using simple way and distribute the manhours over the whole month to get manpower also distributed uniformly over the month you calculate manpower during only the activity durations and the figures you obtained can be only applied to the activity days not to the whole month .. Your approach is correct if you make manpower planning per day not for the whole month but for now I think you better follow your sub-contractor calculation.

Unfortunately I don't have experience in resource loading so can you tell me what is the problem if the resource utilization for some activities is 0.35 day ... and if it is really a problem and affected the budgeted hours distribution ... why you used his figures for your calculation? and why you don't ask your sub-contractor to fix it and re-allocate his resources?!

Sorry for late reply

Regards

Hany

Mike Testro
User offline. Last seen 28 weeks 2 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418

Hi Rajkamal

260 mhrs per month is often applied in middle east construction contracts.

It is a short sighted philosophy because you will get the same production output from an 8 hours shift as you will 10 hours.

Then in the summer months (June July & August) and Ramadan the rule is 6 hours per day.

There are 52 Fridays in a standard year which equals 4.5 Fridays a month - thus the 260 hrs a month will exceed th 10 hrs per day - so the contract rule is nonsense.

Work 8 hrs a day and increase the gang by 20% and production will fly.

Best regards

Mike Testro

Leonardo Caoile
User offline. Last seen 3 years 13 weeks ago. Offline
Joined: 11 Jul 2011
Posts: 22

Hi Rajkamal!

You have to verify the client specifications - "As per contract client has specified that 260mhrs/month need to be considered as basis for planning" - is not enough. But base on this initial data, this is my understanding:

1) That, the basis of planning shall be 10mhrs/day per person using 6-days work week.

2) That, by industry standard, we use 26 days per month (if only friday is off). 

3) 26 days/month x 10mhrs/day = 260mhrs/month.

From the above data, the planner must determine the number of workers needed to execute the projects. This should be done in coordination with the Project Team.

NOTE: if its 5days/week, then you must use 22days/month which will only give 220mhrs/month.

I hope this would help in your query.

Rajkamal Tangirala
User offline. Last seen 24 weeks 1 day ago. Offline
Joined: 29 Mar 2010
Posts: 9

hi Rafael,

it is 260mhr/ month, ~66mhrs/week, ~11mhrs/day.

I have calcualted the no. days on 5day/week which i have overlooked. Only Friday is off.

The subcontract is for total construction phase for the project. Where as the E&P are performed by our company.

I dont think I can give the value u have requested me.

Kindly have look at the spreadsheet i have placed in my post.

Rafael Davila
User offline. Last seen 11 hours 53 min ago. Offline
Joined: 1 Mar 2004
Posts: 5240

RE: As per contract client has specified that 260mhrs/month need to be considered as basis for planning.

Unless I am missing something there is something wrong with the above statement.

260mhr/month = 13mhr/day on a 20 days per month calendar this yield 1.626 md/day on an 8 hours shift.

Something looks wrong.

How many workers on average will be required to deliver the job within contract time? Give me a number that makes sense to you, based on your experience in planning such jobs. 

In lack of any details you can gross estimate labor cost as some % of total contract/subcontract cost, say 30%.  Divide it by number of contract/subcontract work days to get average budget labor cost per day, then divide result by average labor cost per day to get an average of required workforce. 

Keep the calculations confidential just give me your estimate of average workforce required.