Hi



In MS Project 2007, when you change overtime work, why task duration gets changed? - this is strange!

The duration comes to less than 1 day (in decimals) when i increase the overtime work!!

thanks
hammad

Assigning overtime work always drops the duration of tasks. The amount of overtime is deducted from the total work on the task and the lower number is used to recalculate duration. Overtime is considered "off the working calendar".

Hi JulieS

Thanks for the reply. I have a little understood you.

Why by increasing overtime work the assignment percentage only gets increased? If it was 100%, after increasing overtime work, that becomes 120% for example, because the resource is working more than the default work hours or what is defined in his calendar, right?

What's the point of decreasing the duration, i am not getting it, can you please elaborate a bit more?

thanks

It sounds like you are not really using the Overtime Work field -- just increasing a resource's hours per day?

If you are using Overtime, you have to assignment it to the task specifically. Increasing the number of hours the resource is scheduled (in the Task Usage or Resource Usage view) just increases assignment units.

You are correct, assignment units over 100% means that the resource can create more than 8 hours of work (effort) in an 8 hour duration.

Decreasing task duration means the finish date moves in (earlier). If you start moving the finish date of tasks in then you might be able to finish the project earlier.

Hi JulieS

No, I am changing a value Overtime work column in the Resource Usage View and this is effecting the task duration.

please guide in this regard

thanks

As I explained, overtime work always decreases duration -- however it should not be changing assignment units.

Perhaps if you tell me what you want to accomplish, I can be of more help. But again, assigning overtime work will change the task duration.

Hi

But i didn't understand why overtime work changes duration. What is the relation between them. And is there a formula, how overtime work effects the duration value?

practically speaking, if a resource works 8 hours, 10 hours or whatever hours in a day, the duration remains the same 1 day. Similarly if a resource works 8 hours and does 2 hours overtime, the duration still remains 1 day, by adding 2 hours overtime work duration doens't change... but why then it does in MS Project?

thanks

If you have a task of one day duration and assign one resource at 100%, Project calculates the work = duration * assignment units.

So, 8 hours of work for one resource at 100%. So now you decide to assign two hours of overtime. By assigning overtime project subtracts the 2 hours of overtime from the 8 hours of "regular work" equaling 6 hours. The definition of a day by default is 8 hours (set in Tools > Options, or File > Options in 2010). So there are now 6 hours of regular work and two hours of overtime. The 6 hours are now used to recalculate duration.
6/8 = .75 days

Again, there is a significant difference between assigning overtime and tracking overtime. If you originally had the resource scheduled for 8 hours of work and you enter 10 hours of actual work, Project will increase the assignment units. If you enter 8 hours of Actual Work and 2 hours of overtime, the assignment units will stay at 100% without triggering an overallocation.

It really does matter where you add the overtime and whether you add it to the Overtime work field or Actual Overtime Work.

I hope this helps.

Julie

Hi JulieS

I am trying to understand this. But really the "regular work" should remain constant at 8 as it is regular. .Overtime work shouldn't change it.


Hammad

Hi Hammad,

I'm afraid that is not how Project deals with it. Work is the sum of regular + overtime work. So assigning overtime decreases regular work. This is just how Project chooses to calculate it.

Hi JulieS

Thank you for your guidance


hammad

You're welcome and thank you for the feedback.