Employee A estimates that she spends 20% of her time working on process step 1.
Employee A’s supervisor requires Employee A to never process any work
appearing on her desk for process step 1 if work from value stream C is
available to process first.
Employee A estimates that this situation occurs 15% of the time when process
step 1 work appears
Calculate AOP as
% Time spent on process step × % Time interrupted by higher priority work
= AOP 20% × 15% = 3.0% AOP