If it takes 3 men to complete a project in 1 day, how long does it take 9 men to complete the same task?
1/3 of a day??? Or is that to easy???
You are assuming the work to be completed is linear in time and the additional men are able to contribute their efforts in the same fashion.
But what if the work is nonlinear? What if the work to be completed is sequential, and that time to complete each section cannot be sped up, and/or additional men cannot be accommodated?
For example, if the original three men are each responsible for completing one-third of the work (which can only be done by one person in each case), that it takes each man seven hours individually to complete their third of the work, and the remaining one hour collectively to complete the project, using six additional men fails.
If the job can be done by 3 men, then obviously the other men have to find something to do to make themselves useful. At least one will be the big boss, then 2 more to be senior VPs, 3 middle management, 1 department head, and of course the 3 actual workers. The department head has to write the work order, which has to go to the middle managers for approval which should take about a week (they only meet once a week to approve things you know). Then this has to go to the VPs, who reject it just because they can, then the department head has to amend it, then it gets approved again, and finally the guys get to work, but only when the department manager is ready with his report to the big boss about what a wonderful and necessary job his workers do.
All in all I figure about 5 months.
Fantastic answer, comp_geek