Original Duration

Hi



I don’t think there will ever be a "correct number of workers". All we as planners can do is to take an "educated quess", that is based on our past experience and also by applying the does it "look and feel right factor".



Planners that don’t have sufficient experience a quick chat with the other Planners / Supervisors / Engineers can often help. Also some companies have standard crews / mixes for certain type of work, that has been built up on past experience.



Like all planners after I have set up my programme with the OD’s in place. logic etc, I schedule and check my Critical Path, dates / milestone etc and look at the Histogramms / Curves. It is only then you can see how good the durations actually are, as problems with resource loading, missed dates come to light.



This is when we need to start adjusting crew sizes to effect changes in durations, reviewing logic etc., so that we can produce a workable plan that meets the project requirements.



Well I suppose that is what we are paid to do as planners !!!!



Regards



John.

John.



I understand your proposed method but consider the interaction of activities,



how could we decide on the correct number of workers / each crew ???



i mean by correct Number say instead of 6 i want 10 so does the site allows that. what are the other activities on site during my assumed crew size (so you need to know a bit about the schedule) wouldn’t it be crowded, actually from my perspective you need to set the OD with reasonable assumbtion (like your’s 6 workers/crew) then if it fits it would be okay if it does not you need to rechange the assumtion so it is a cyclic work until you reach an OD fits the situation,



What do u think, John???

Hi,



sometimes the OD is controled by others, then you need to calculate the resource you need.



Anyway, experience is important.

But how can a planner has those experience of so much different tasks & trades in different area?

Hi



For the Orginal Duration (OD):



First calculate the manhours for the specific piece of work, then divide by what you consider a resonable sized crew of labour that can practically handle the work.



eg. Say you have 1200 manhours worth of steelwork to erect, using a crew of say 6 men working a 10 hour day would give you: 1200/6*10)= 20 days (OD).



You get other durations that will be fixed ie Procurement of materials / equipment, concrete setting, buildings drying etc.



To agree durations you have to discuss with the people that will be involved in doing the work, i.e. supervison, engineering, procurement etc, as they will have a good understanding of the time required etc



Regards



John

Hi Vinai...



The basis for calculation of Original Duration (OD) for any activity is (Resources)



(labors- material-equipment...etc)



And this is need experience to do it as i know.



And you can work together with your other Department(engineering- Material-construction)..to help you in that.



regards

salah