Timetabling Algorithms?

Phil John queries: "I'm developing a system for a University Student Union which employs 400+ student staff. Allocating shifts up till now has been a manual task keeping 1 member of staff busy for at least a day. I've been asked to implement a Web/SQL based system to get student availability (which changes each week), get shifts required and automatically allocate shifts. Now, here's the problem: how do I handle the timetabling bit? Most solutions require genetic algorithms and while I can understand and implement them (having a degree in AI and CS) I'm not going to be around after the summer and this creates problems for people maintaining my code. Cheers for any help you guys (and gals) can give me!"