I have a trouble. Consider a task 'developing software'. This task has 1000hrs of work. A single developer might work for 1000hrs, or two for 500hrs. Duration, in a standard 5d with 8hr/day, is 125 day with one developer, or 62.5 with 2 developer. However, there's a third resource, the team leader, that need to spend 5% of total work on the task, but should not affect the duration. In MS Project, when I insert this third resource, the task duration is recalculated and work is spread on this resoure, like 475hr for each of two developers and 50 for the team leader.

Is there a way to prevent this?

3 Answers 3


However, there's a third resource, the team leader, that need to spend 5% of total work on the task, but should not affect the duration.

If the work is intrinsic to the task, it should increase its duration, otherwise what are those 5% your team leader is working on? It's 5% of the 100%, not of the 105%.

If the work is external to the task (a "management overhead"), then it should be placed outside of the task.

Likely (it is an assumption) your team leader will have his work spread all over the project as some percentage of his time, not a percentage of each task. In this case you there is nothing to track in the project plan, since such work is not "completed" or "not completed" - it is just being done on a regular basis and there is no progress to check upon. You can account for this in a flat calculation over your project total duration, and adjust this resource's availability correspondingly.

standard 5d with 8hr/day

On a side note, you should never plan for 8 hr/day - this is not achievable because you cannot get 100% productivity from the person on a constant basis. Allow for some buffer here (or in your estimates, for that matter - depending on who you want to pay for this).

  • I understand that is better to place it outside in a dedicated task. Both tasks are fixed work, however the duration of supervision task should be linked to the duration of sw devel task. Is there a simple way to do it with MS Project?
    – Ste
    Dec 31, 2014 at 9:20
  • @Ste, I think yes, it is described here: pm.stackexchange.com/questions/9168/… Dec 31, 2014 at 22:05

You are making this far too complex than it needs to be. If you want duration to be fixed, then choose that option and distribute the 1,000 hours among the developers and add an additional x number of hours for the team lead. If x is 50, then the work planning value becomes 1,050.

You need to remember you are creating deterministic planning values on work, duration, and resource units that are, in reality, extremely probabilistic and somewhat independent. These deterministic planning values establish the baseline and let you calculate costs and price if you are selling the work. Once that baseline is established, reality will not look anything like that. These variables will appear very random and are largely random.


If the task is Effort driven (the default in pre-2010 releases and for all Fixed Work task types) the total work on the task remains the same and will be divided among the assigned resources based upon their assignment units. By default, the duration of the task is recalculated.

So, a couple of options to accomplish what you need:

  • Temporarily turn off Effort Driven for the task. (You'll need to set the task as Fixed Units). Double click to show the Task Information dialog, change the task type to Fixed Units and uncheck Effort Driven on the Advanced tab. Assign the supervisor resource at 5%. His/her work will be calculated of based upon Duration * 5%.


  • Use the Task Form and enter the estimated work for the supervisor upon assignment. Even if the task is Effort Driven, Project will not recalculate duration as you have manually added the work for the supervisor.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.