There are 100 machines in a semiconductor manufacturing company and the machines are grouped with 4, that is, each group consists of 25 machines. It is assumed that there are 10 different types of jobs (Job 1, Job 2, … , Job 10) and each processing times are exponentially distributed with means of　10, 21, 22, 50, 3, 14, 83, 23, 16, 67 hours, respectively, and the setup times for each job are normally distributed with N(3, 3), N(4, 1), N(10, 5), N(16, 3), N(5, 2), N(11, 5), N(4, 4), N(19, 6), N(3, 1), N(5, 2), respectively (Unit is hour). Generally, it is known that the probabilities that the jobs have a certain defective for a machine are same 0.01. Each job has to pass group 1 to 4 (the order does not matter!), but a job with a certain defective has to visit group 4 definitely for 3 unit hours. Provide an algorithm to minimize the total machine operation time and prove your suggestions with computer simulations.

我写了很多次，老师都说不对，最后说叫我从生产计划优化入手，希望学过的人可以指导一下，谢谢！