Scheduling is not always a very simple thing. there are a lot of rules and contingency's for certain times.

Putting in set time slots does not give you this. it leads to inefficiency in schedules, because we don't just have inspections on those specific time slots. This leads to potential gaps in the inspectors schedule where he has nothing to do.

Solution: A deeper level.

A solution to this is to add a deeper level of rules for scheduling times. Basic IF statements will suffice. or a series of yes no questions. If next appointment is at 2:00 pm and is less than X miles away the open time should start at 10:00 am instead of 9:00 am.

That's just one example.