You may use math structures while problem-solving during the case. For example, if you have to understand why our factory has 4 FTEs doing the cleaning while Competitors use just 2 FTEs, you can structure it like:
Frequency of cleaning per day * working days * FTEs per 1 cleaning
After deriving the numbers you may find that a single cleaning procedure is longer and you may want to check if the problem is in: People / process / technology
Best