I am using MS Project Standard 2003 SP3 and have experience instances in which the automatic calculation of work effort fails to work when I change duration. Has anyone else experienced this and know why it happens and how to prevent it?



I created by project schedule with if effort driven and began to modify some resources. As expected, the modification to the resources updates the durations for the tasks, so I change duration back (since project is fixed duration on tasks) and the work updates as expected, so I proceed down the remaining 600 lines. Upon reviewing the resource usage I notice some are way off and find that not all the work efforts updated. In order to 'game' project I enter a very large effort (555) and then enter the right duration and magically the effort calculates properly.

Needless to say I would rather not go through all 600+ lines again in the future and would prefer to not have to check every line item I change to ensure project calculates as expected.

I would very much appreciate any feedback or words of advice. Thanks

John

If I am understanding correctly, you have Effort-driven checked for all tasks.

Effort-driven means that the resources work together on the task, sharing the work. Adding more resources will not change the amount of work.
If you check Effort-driven for a fixed duration task, you are fixing both work and duration, leaving only one variable (units) that can change if resources are added or removed.

Are your tasks all set to effort-driven, fixed duration?

The tasks are set to effort driven, fixed unit which was the default. It was working when initially set up but changes to duration do not always recalculate. Since my durations are fixed and I want my resource allocations to drive the total work, then it seems I want to set fixed duration, right?

I should add that this is an 'odd' project because the durations for tasks are fixed by the vendor since the work is fixed price and their process is standard. This is the reason the resource allocations can change, but the task duration needs to remain the same and work effort changes.

Are your calculation issues related to changing duration or is the trouble arising when you add / remove resources?

If you are changing the duration, then you don't want Fixed Duration. Perhaps something here will help you:

• Effort-driven does not affect what happens when a variable (such as Duration) is changed; it only influences what happens when you add or remove resources.
• Fixed Units: if you change Duration, Project will recalculate Work. If you change Work, Project will recalculate Duration.
• Fixed Units, Effort-driven: If you add an additional resource, Project will recalculate Duration.
• Fixed Units, NOT Effort-driven, If you add an additional resource, Project will recalculate Work.

Remember, nothing is recalculated the first time you add resources.

I suspect you want Fixed Units, NOT Effort-driven. This way if you change Duration, Project will recalculate Work. And if you add resources, Project will recalculate Work.