How to make Duration take resouce's availability into consideration

[marcarls]

Hi,

In my project the resources availability is changing from week to week. I have entered this in "Resource Information". For example person A is working 50% of a 40 hour week. BUT when assigning him a 40 hours task the duration of task will still be presented as one weeks, instead of two.

Does anyone have a solution for me

Thanx in advande

 

[jancebk]

Did you enter your 40 hours into the duration field?

There is a difference between duration & work effort.

Try using the Task Usage View - it shows tasks and assigned resources. The default table with that view should have columns for Work & Duration. You will probably see that your resource is assigned 20 hours of work for that 40 hour duration task.

Hope this helps.
Jan

 

[marcarls]

Yes I entered 40 hours in duration using the Ghant View. When looking at the resource it says that he should work 8/hours per day with that task, not 4 as i would expect.

Does the blue lines in Ghant chart represent work effort or duration? I expect MS Project to adjust the length of the bar depending on which person I assign the task to. Perhaps I have wrong expecations, this is all new to me.

 

[PDQBach]

Here beginneth the first lesson:

Work = ResourceUnits * Duration.
or W = U*D

Assume that one man can dig 50 feet of trench in one day and you need a 300 foot trench.

You could assign one man to dig the 300 foot trench over 6 days. Or you could put two resources to work at 100% for 3 days and you will still get 6 workdays of effort (enough to dig the trench) but in a duration (or elapsed time) of 3 days. Or you could put six resources to work at 100% for 1 day.

From this you can discern the second lesson:

Work <> Duration.

Here's another way you have to look at ResourceUnits. If I tell you to write a report and tell you to spend 8 hours on it and to have it ready in one day then your ResourceUnits are being used at 100% of their capacity.

Work = 1 day
ResourceUnits = 1 at 100%
Duration = 1 day

If I tell you I want you to write a report and have it for me in two weeks time and you expect to take 24 hours of work to do the research and writing then you can see that:

Work = 3 days
ResourceUnits = 1 at 30%
Duration = 10 days

In other words, your ResourceUnits are being used at 30% of their capacity.


So ... you have three items: Work, ResourceUnits and Duration and you can see that they have an elegant mathematical relationship to one-another.

What happens if you want to change just one of those items? If you want to increase Work then you need to increase ResourceUnits or increase Duration. But which? And by how much?

Here beginneth the second lesson:

There are three task types:
Fixed Work
Fixed Units
Fixed Duration.

Depending on what you are changing and what you want Project to modify so that the equation remains mathematically accurate, you will make a task one of those types.

If you make the task Fixed Work (in other words, you will not allow the amount of work in a task to change when you make your entry) then you can change ResourceUnits and Project will automatically calculate the necessary change in Duration to keep the W=U*D mathematical relationship true or you can change Duration and Project will automatically calculate the necessary change in ResourceUnits to keep the W=U*D mathematical relationship true.

I will leave it to you to figure out what happens with the Fixed Units and Fixed Duration tasks.