Rate Routings Partial Costing

Need the help of this forum please. We are a discreet manufacturing firm with specific operations for our products. In many cases, we will perform an operation only a portion of the time, say 10% or 15%. I'm trying to find a way to have the cost of these operations represented in the standard cost based on their prorated frequency. I thought cost relevency was the ticket, but that didn't work, and in searching this forum for solutions, determined it truly was not the answer.

is the answer in the control key for the operation? At present, the control keys we have available are either cost yes, or cost no. In other words, cost at 100% , or cost at 0%. Do I need to have a custom control key created? If this isn't the proper approach, then is there another?

Thanks,

Roy