It's akin to a good algorithm for avoiding memory fragmentation - allocate your largest blocks first. Assuming you need a contiguous block of time for each cas

It's akin to a good algorithm for avoiding memory fragmentation - allocate your largest blocks first. Assuming you need a contiguous block of time for each case, you should schedule the longest case that you expect to complete in the time available, leaving a bunch of cases you can easily slot into whatever time is left.