Resource Scheduling

 Hello, I have an operation 'cooking' that can be done with any of the 6 ovens. When I do the job scheduling, it always assigns the oven with the higher capacity (less duration). Is there a way to choose which ovens will be used in a certain production? I am trying to use resource groups but it keeps assigning only one oven from the group.

Also I need to report in production the real resource(s) that were used (for example if the scheduled resource was not operative). Is it possible to choose any other resource?

Thanks