I was employed with a large company about 10 years ago, in which I was tasked with writing their rostering solution in c# as a desktop client. They had looked for a product, but none existed that would allow them to staff rosters according to a large number of equity rules. Unfortunately, just when the project was about to be deployed, the company was absorbed into another company putting a hold on any new projects, including my project. It was from that experience that I learned the basics about rostering.