Define each stage by exit criteria that someone other than the rep can verify. A qualified deal means the application is confirmed in a core category, a named contact beyond purchasing is engaged, and the buyer has stated a timeline. Discovery is complete when there is a written problem statement in the buyer’s words, the cost of the problem is quantified, and a second contact is engaged. Attach a typical duration to each stage from your own history, and write the rule for what happens when a deal exceeds twice that duration.