Let's say I have a group of people and 7 different jobs that have to be done every week - one per day. Each job requires one person. How do I distribute the jobs among the group so that both the "vacation time" between each workday and the time between doing the same job twice is constant throughout the group? In other words, I need an even distribution of both workdays in general and of specific jobs. What tools are used to solve this kind of problem? Thanks.