“The GNU Linear Programming Kit is a powerful, proven tool for solving numeric problems with multiple constraints. Get an introduction to GLPK, the glpsol client utility, and the GNU MathProg language to help find the best solutions to complex numeric problems. Then, learn to solve the problem of optimizing the operations for Giapetto’s Woodcarving, Inc., a fictional toy manufacturer.”
Yet another nice article fro IBM
Reminds me of solving simplex and other methods at university 
It’s good they provide mathematical background, at least basic.