'Duration given by percentage of Base value'

Copper Contributor

My company uses a "Effort Estimation Template" which uses a base value (estimated time) to calculate the duration for different tasks. Example: Base value 10 Days, Analysis needs 0.4 * 10 = 4 days. Is it possible to define the duration in MS Project as a formula for different tasks ? Like Task1=0.1*10, Task2=0.05*10 and so on. We would like to create a template for our standard tasks where only the base value needs to be changed. 


Thank you in advance. 

4 Replies
Arend_M --

There is no way to create a formula in any default field, including the Duration field. But what you can do is to create custom Duration fields containing the formulas you describe, which are based on the Duration value that is entered. The custom fields will then automatically update when the Duration value is entered. Hope this helps.
Sorry but something doesn't quite gel in your description. You say you use an "effort estimation template" but then you talk about duration. In Project effort (work) and duration are two different parameters. Duration is the time span during which a task is performed. Work is the amount of estimated effort to accomplish a task. If a single full time resource is assigned to a task, then the duration and work will be the same but this is often not the case (i.e. multiple resources are assigned or a single resource is not full time on the task).

So what exactly does your "base value" represent?


Hi @John-project thanks for the answer.

I have expressed myself a bit misleadingly. The base value is an estimate of working days (8 hours) for a project (different for each project). Depending on the task, these are extrapolated with a multiplyer 5%, 10%, etc. including buffer etc.. These are experience values that are needed in the company for certain processes. Different tasks different resources you are right.

I would now like to create a template in MS Project where I have my standard tasks, where the duration is specified on the basis of the "base value". BSP. base value 10, Task Analysis = 10*0.4 = 4 days for a Business Analyst, Task Test Automation = 10*0.2 = 2 days Test team member, etc.

I want a field where I can enter my base value and then all standard tasks durations should be scaled up automatically based on the base value.

Is there VBA for MS Project?
We use excel so far but it would be nice to have something like that in project so you don't have to transfer anything.


Sorry but my head is still spinning about your "base value". And what is "BSP"?


You give an example of Task Analysis equals 4 days (computed) for a Business Analyst and Task Test Automation equals 2 days for a Test team member. I still can't tell if that is time span (duration) or effort (work).


One thing I can answer for sure. Project does include VBA but of course the object model is quite different from the Excel object model. That tends to "trip up" (i.e. frustrate) a number of Excel users who attempt writing Project based macros.


Can you get there from here with Project, and some VBA? Yeah, probably, but in order to provide more help I need a clearer understanding (i.e. explaining to a 3rd party not familiar with your "company processes") of your intent with respect to Project's definition of duration and work. Maybe a simple screen shot of a Gantt Chart example would help. You know, a picture is worth 1k words kinda thing.