Whether they can configure and quote your product unaided by week four. Give them a real inquiry from the past six months with the same information the original salesperson had, then compare their quote line by line against what actually went out, checking configuration, pricing, lead time, and the customer note. Passing by week four indicates a rep on track. Failing to pass by week six calls for a different training approach immediately, while there is still most of a year to correct it.