It’s a problem in almost every shop to some extent. Many causes of parts waiting can be reduced or eliminated with some simple fixes. 1: When anyone (tech, advisor, etc.) is 90% sure that a part will be needed, order it now. 2: Restock common parts from primary vendors daily. 3: Assign parts handling to one individual as much as possible. 4: Check the schedule for tomorrow and beyond every afternoon and order parts likely to be needed. Finally, when implementing these or any other parts handling systems, make sure that each one is scheduled and assigned so it actually happens.