ESTIMATE AND PLANNING

See every fabrication job have many factors - design, location, finishing, time frame etc. Any how find the basic raw materials cost of the job. then count labour cost @ 30% - 40% of material cost, then calculate quantity of very skilled, skilled, semi skilled & unskilled man days. Now find local labour rates & divide labour cost by man days, you will find the required man power +10%. Put it in a bar chart if possible.

MILTON SIKDER, CGM, TSHPL

Its not a difficult job to work out, but it s really only a estimate work. you cannt calculate accurately it. it depends on various conditions, machine, skill, knowledge and sites and region etc. you can find a budget table in your region from local associaton.

and many software can be selected for it. for example exel or project etc.

I believe you are talking about structural steel fabrication. Productivity depends on type ( Light steel , medium steel and Heavy steel ) region ( Europe, Asia, Arab world) and yes offcourse on the man-incharge too.

Normally consider 60-70Mhrs /Ton for Light steel , 50-60Mhrs /Ton for medium steel and 20-40Mhrs /Ton Heavy steel I am giving you the range to accomodate other factors like region and personnel performences. These manhours are only for prefabrication works. For erection they will be different depending on various factors like height , type of joints, location- region, skill of manpower , etc.

Once you calculate the total Manhours then divide by 10hrs to get Mandays and thereafter calculate Manpower by dividing Mandays by duration.

Ex Medium Steel T = 100Tons

Manhours = 100x50 = 5000Mhrs

Hrs Per Day = 10Hrs

Mandays = 500MDays

Available duration is 30 days

Manpower Required = 16.7 ay 18

Now you should be knowing how to allocate welders , fitters, fabricators , grinders , helpers , riggers , foremen , etc- This will be Direct Manpower Only

Akram

There is no set formulae to calculate man power required to weld 100 tons of steel, for there are many variables: 1) Process of Welding, 2) Thickness or weight per foot of work piece 3) Design of Weld joints, 4) Type of filler metal, 5) Position of Welding 6) Design of structure and whether any thermal treatment to work piece or weld is required. If you have answer to the above variables, some one would definetly help you by giving you the parameters of calculation. Mind you! If you want to weld steel structure in shop and on the location at site and at hieght, would vary a lot by cost. You may get help for man-power estimating from manual published by Gulf Publishing Company. Cost of welding varies country to country.

Don't forget to allow for weather, unforeseeable problems, acts of war and God if you are bidding on the job and it has a performance clause that makes you pay if you run over past the due date for the end of the job.

If your crew is used to to working in 30 C summers and you get 3 weeks of 40 C weather the productivity drops through the floor. The same is true for a crew used to 40C in 50C weather or even worse. Two weeks of thunderstorms will drive you mad as well.

Good Luck

Gordon

Depends on these:

• How callous the original designer :-was he lazy -and used only 2 or 3 Heavy Standard sections( fast fabrication)---or was he absolutely a penny pincher-- never overdesigned and used all kinds of optimum/minimum sections(Slow Fab.)
• How generously equipped was your fabshop? EOT cranes,Manipulators,rotators?
• How generous was intermediate storage in your fabshop floor?
• How powerful your Gas Cutter/AirPlasma Cutter and were there enough of these with capable operators?Were Consumables amply/readily issued
• Were there a good size mix of Powerful MIG/MAG, SMAW,TIG,Stick Weld sets?
• Was there a Chaser/Despatcher/Expediter constantly monitoring at various stages of operation?

No formulas possible -- If somebody tells you these are possible --take with a pinch of salt .

Welcome vinodincr4,

Do you have within your organization staff who have performed the type of work you are bidding. They are an invaluable resource even if their experience is not identical to the project at hand.

I can't imagine competitively bidding work I have no experience in or access to someone who does. I do enjoy stretching the envelope where I have just enough experience to grow into a new project.

Good luck

I recommend you using statistics, you may use a calculator or MS Excel, consider this, how much can an employee produce per hour or day, once you havve the answer, devide 100 ton for the amount produce by one person and that should tell you howmany employees you need.

Also, you need to consider age, experience physical strength or skill.

'Berger Estimating manuals" used to carry ways to give you

answers based on detail or on general 'per sq. ft.` costs in the U.S.

There was man/hour data once you provided some construction details.

www.costeng.com people seem to be developing some interesting estimating software that provides automatic access to manhour databases. I see they have modules for piping and I believe other disciplines are 'in the wind'

It's commercially sensitive information and unlikely to be found on an on-line forum, or anywhere else for that matter. These things are best home-brewed by the <...we...> in question.

Good grief. This thread is 15 years old, and the most recent post until now is 12 years old. Geez. If you want to do archaeology, go to Bumfuk, Egypt.