How can you have same resource twice in the same operation - once for fixed time and then proportaio

Hi All

Am new to OPM functionality have worked extensively with discrete, so forgive my basic questions.

In discrete I can set up an operation to have the same resource more than once as a basis of lot and item which is great for adding in a setup or clean up step.  In OPM per operation can I only add the resource once?

The reason I am asking is that I want to do resource alternates depending on the capacity but if I have the resource is two operations (one for running and one for cleaning), I am finding that operation 1 uses the alt resource and then operation 2 uses the primary, which you can probably guess makes no sense at all. So my ultimate requirement is to use alt resource on both operations or not at all.