SNCF is a large railway transportation company that operates 365 days a year and 24 hours a day. In order to schedule a certain category of workers at train stations and ticket selling points, rosters are designed to cover a cyclical demand. However, the highly combinatorial nature of the rostering problem makes it very difficult to solve it manually, and experts spend a huge amount of time to make them legally feasible and to improve a certain number of preference criteria. This paper presents a mixed-integer programming model to address the cyclical rostering problem using patterns corresponding to feasible blocks of seven days and assigning them to each week of the roster. Some valid inequalities are presented to improve the linear relaxation of the model and thereby enhance computational performance. Implementation results are presented, including comparisons with an alternative daily-variables model Povzetek: Opisano je optimirano cikli?no razporejanje delavcev z aplikacijo za podjetje SNCF. 1

Rostering is a crucial planning process in an airline’s overall scheduling hierarchy. Besides addressing the issues of crew utilisation and crew costs (which represent two of the major expenses in running an airline), a rostering tool must also cover the question of quality requirements. The quality of service can be improved by having the rostering tool take into consideration the skills of individual flight attendants during the rostering process. The quality of work life that an individual employee enjoys depends on his or her ability to participate in the rostering process. To an extent, this participation involves the employee's ability to determine his or her own work schedule, which in turn also impacts his or her job performance. Timely and ubiquitous access to rostering information therefore represents a crucial benefit for employees, as it enables them to not only query data on schedules, but also to submit their preferences at all times and in any place. In this paper, we present the architecture for RosterBuilder, a sample framework for flexible rostering at airlines and show how RosterBuilder can be integrated into modern computing and communication environments. We focus on deriving functional requirements that apply to most airlines using a rostering concept and specify those requirements in use case diagrams that follow the UML formalism. Our analysis considers the user groups that are involved: crew members, crew assigners and crew operators. Considering