We see that all possible lists are generated anyway, in the first loop, so we have the best possible case when the first list permutation generated is sorted. Thus, this gives 1 work unit for the second loop, giving us $$ n! +1 $$ work units in the best case. Similarly, in the worst case, the last list is sorted, giving us: $$ n!+n! =2n! $$ work units.
Work Step by Step