Schedule & Man Hours

[Alwayslearningelec]

How do you determine that based on the schedule given to you and the estimated man hours you can do the work in that amount of time(given you have the men). What are some determining factors?

I mean if you do the math(and I'm am making numbers up) and say you have 1,000 hours and 1 month to do the job. you would divide 1,000 by 20(working days) and that give you 50 hours a day then divide that by hours worked per day and that's the number of men per day.

I guess space, work available etc....

 

[mkgrady]

How do you determine that based on the schedule given to you and the estimated man hours you can do the work in that amount of time(given you have the men). What are some determining factors?

I mean if you do the math(and I'm am making numbers up) and say you have 1,000 hours and 1 month to do the job. you would divide 1,000 by 20(working days) and that give you 50 hours a day then divide that by hours worked per day and that's the number of men per day.

I guess space, work available etc....

That would work for your average crew size but in reality you must factor in that you can't start with the full crew on the first day, nor would you assume you would have a full crew on the last day. A graph of the crew size would look less like a straight line and more like a bell curve. Additional things to consider are normal weather delays. You generally can not get a time extension for weather delays unless they are more than normal. And lastly you must look at the things in the schedule that must be complete before you can start various tasks

 

[Alwayslearningelec]

That would work for your average crew size but in reality you must factor in that you can't start with the full crew on the first day, nor would you assume you would have a full crew on the last day. A graph of the crew size would look less like a straight line and more like a bell curve. Additional things to consider are normal weather delays. You generally can not get a time extension for weather delays unless they are more than normal. And lastly you must look at the things in the schedule that must be complete before you can start various tasks

I do understand ramping up/down manpower...... I just was curious as to what determines whether you can meet the schedule or not with the accounted amount of manpower. Thanks.

 

[gadfly56]

I do understand ramping up/down manpower...... I just was curious as to what determines whether you can meet the schedule or not with the accounted amount of manpower. Thanks.

Another thing to consider is crew efficiency, whether it's a one-man crew or a ten-man crew. You usually can't get 8 hours per day of work from every person. I know, a few hard cases here will chime in that "they better be giving me 8!" but the fact is, that between smoke breaks, pottie breaks, mandated breaks (ie union or other contract), safety talks, daily meetings, and a dozen other time sinks your productive time is going to be 6-7 hours per day. The various estimates provided by RS Means and others for how long it takes to do "X" don't take this efficiency into account. So if the estimating software says your total man-hours on the job are 1,000 you have to apply the efficiency factor to this number. If productive work is 7 hours in work day, you'll need the equivalent of 1,142 man-hours to actually complete the work. That's about 14% more than "the book" says you need. With margins what they are nowadays, that could break a job.

 

[Smart $]

I do understand ramping up/down manpower...... I just was curious as to what determines whether you can meet the schedule or not with the accounted amount of manpower. Thanks.

Just speculating here as I have no experience in this area...

Once you have determined the average men per day, as mentioned, you have to account for not having that number on site every day of the project. If manpower on site each day follows a standard bell curve when plotted, you'd peak at approximately 1.8 times the calculated average men per day. If you can place this many men on site for the bulk of the project, you should be able to meet the schedule.

 

[iwire]

I am curious why a estimator is that concerned with the manpower loading / schedule.

I am not that experienced in this either but as I understand it our estimators estimate the total hours, our person in charge of labor determines how many guys and when based not only on that particular jobs needs but the labor needs company wide.

 

[Alwayslearningelec]

I am curious why a estimator is that concerned with the manpower loading / schedule.

I am not that experienced in this either but as I understand it our estimators estimate the total hours, our person in charge of labor determines how many guys and when based not only on that particular jobs needs but the labor needs company wide.

Because isn't there a case where your estimated hours and schedule given to ou won't work... Meaning there is no way to complete ht amount of work in that period of time without OT etc. I think an estimator should be very aware of the schedule and hours estimated. Or how out if your a union shop and there re pay increases every year and the job is two yearsc long... You need o know what portion of the work/hours will be done in the increases rate year

 

[petersonra]

We run into this all the time.

Say a project takes 1000 hours. And you can get 35 productive hours per week per employee. That is 28 manweeks.

Even if you have 28 people to assign to the project, it is almost never going to be practical to put 28 people on the job and expect it to get done in a week.