How to model this?

[excelos]

Hello,

I want to model the processing of some cases, so I know the process time of each case and the number of employees, so I can find the end date.

However, depending on the deadline, the cases may need to be reprocessed every a fixed number of months, so that the total number of cases may increase depending on the end date.

How can I model this? I find difficulty because the number of cases to be reprocessed affects the end date, but also the end date affects the number of cases to be reprocessed!

Any idea?

Thanks