Difference between fixed work, duration and units

Is there anyone who can explain the difference between task types (Fixed Work, Fixed Duration, and Fixed Units) and which types should be used when. Thanks for any information.

If you change a resource assignment to a task, then microsoft project will always balance the equation. Duration x Resource Units = Work. So, for instance, if you double the number of resource units assigned to the task, then Project can balance the equation two ways, that is, divide the Duration by 2 or increase the work times 2.

How to set 4 metre work per day target in Microsoft Project

Pls Help

On the same lines, I have created a schedule that each task will take a specific amount of time. And I have a resourse for that task that can work 80% of the time.
example: CNC MILL - 24 hrs. Roger 80% (resource)
We only have one mill and one resource. should I use fixed duration? I had fixed units, and it had the resource working 10 hrs one day and 4 the next.
also, is there a way to update the whole schedule to a fixed duration, or will I have to do each individually?
thanks, MC

Quote:

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Originally Posted by mcam

On the same lines, I have created a schedule that each task will take a specific amount of time. And I have a resourse for that task that can work 80% of the time.
example: CNC MILL - 24 hrs. Roger 80% (resource)
We only have one mill and one resource. should I use fixed duration? I had fixed units, and it had the resource working 10 hrs one day and 4 the next.
also, is there a way to update the whole schedule to a fixed duration, or will I have to do each individually?
thanks, MC

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Yes, you can try to use the fixed duration and to create it follow the below steps:

1. Insert the Type field into the Gantt Chart view
2. Enter the task name
3. Change the Type field to Fixed Duration
4. Enter the Duration
5. Enter the Resources
6. Effort will be calculated by MS-Project

Quote:

---

Originally Posted by mcam

On the same lines, I have created a schedule that each task will take a specific amount of time. And I have a resourse for that task that can work 80% of the time.
example: CNC MILL - 24 hrs. Roger 80% (resource)
We only have one mill and one resource. should I use fixed duration? I had fixed units, and it had the resource working 10 hrs one day and 4 the next.
also, is there a way to update the whole schedule to a fixed duration, or will I have to do each individually?
thanks, MC

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In addition to Einstein's comments about how to set several tasks as Fixed Duration, I would also make a few more comments.

In your scenario, I would set the task as non-effort driven.

Is the CNC Mill a resource or a task? If the CNC Mill is a resource, I'm guessing it is a machine and I'm guessing Roger is a human resource. If you assign the CNC Mill to a task, Project will calculate work based upon the task Duration * Assignment units.

So if you assign the CNC Mill to a two-day duration task, project will calculate 16 hours of work -- assuming the CNC Mill has a calendar which allows 8 hours of work per day.

If you then assign Roger and the task is Effort-driven the 16 hours of work in total will stay the same and if the task is Fixed Duration, the assignment units for the CNC Mill and Roger will be calculated at 56% and 44%.

I'm guessing this is not what you had in mind.

There are two issues to address: Effort -driven
and
Task Type

In the case of you need both a machine and a person to complete the work on a task, I would set all tasks to non-effort driven. (Add the effort driven field and set all to "no").

Task type discussions really boil down to which of the three values work, duration, or assignment units do you not want Project to alter if you change one of the other two.

See the earlier posts from Gérard Ducouret, Mike Glen, and Dave for a pretty thorough discussion of what task type does.

I hope this helps.

Julie