Solution of Large-Scale Railway Crew Planning Problems: the Italian Experience

Crew scheduling is a very well known problem which has been historically associated with airlines and mass transit companies; recently also railway applications have come on the scene. This now happens especially in Europe, where deregulation and privatization issues are forcing a reorganization of the rail industry and better productivity and eecient services are strongly required by the market and the public ownership. Therefore, this sector is showing an increasing interest in Operations Research and Management Science. Railway crew planning represents a hard problem due to both the dimensions and the operational/regulation constraints involved. This paper gives an account of the development of a new crew planning system set up by Ferrovie dello Stato SpA (the Italian railway company) in cooperation with the University of Bologna. 1 European railways: a new scenario The European railways are being reshaped by a new phase of their historical life cycle, where privatization and deregulation are the underlining themes of the sector. This also follows general European Union (EU) policy directives concerning the separation of the railway system into separate enterprises: infrastructure or track management companies, and transport or train operating companies. The infrastructure company should retain state control in the rail business through natural monopoly or government regulations and investments. On the other hand, train operations should give rise to a number of independent and more business-oriented companies, which have access to the infrastructure via a market mechanism such as payment of track fees. This represents a major change from the traditional status of the European railways, usually regarded as totally state-owned and vertically-integrated industries. Although this scenario takes diierent forms in various European countries, it is nevertheless established as the current trend and long-term objective of the railway industry. (However, some protected segments, such as regional and local services with social interest , may not be aaected by these objectives.) The new rail policy, which has close 1