Minimum duration in project model

[Augusto Carena]

Hello,

I'm currently developing a project model to be used in gaming mode. My concern is about introducing the concept of "minimum duration" for a phase - due to constraints of various kind - so that (e.g.) a 100 units job must be done by 5 people in 20 weeks (or more) but not by 10 people in 10 wks.
As far as I can see, in literature the problem is faced using an exponential delay in the rate equation. My need is instead to let players decide how to allocate people, reproducing the minimum duration constraint.
Currently I manage it dinamically limiting the actual work rate to a maximum rate (original scope/minimum dur) but it is not satisfying (lacks in flexibility, does not allow any partial recovery when late, etc.).
Have you any suggestion about it?

Thanks in advance

Augusto Carena