Optimization problems are difficult! You may want to check out the May 2003 issue of Dr. Dobb's Journal. There is an interesting article: "Dynamic Programming - Looking for 'simply the best'". The author presents a C++ routine that uses what he calls "dynamic programming" that discards sub-optimal solutions (hence avoiding unnecessary computing time).

You may also want to check out the September 2001 issue of FoxPro Advisor. There is an interesting article with source code dealing with Genetic Algorithms - another optimization technique. However, genetic algorithms do not guarantee the "best" solution to an optimization problem - they provide a "best guess" answer which is a generally good enough for most scheduling problems.