@CONFERENCE\{IMM2007-05264,
    author       = "J. J. Groth and J. Clausen and J. Larsen",
    title        = "Extended abstract: Optimal reinsertion of cancelled train line",
    year         = "2007",
    month        = "mar",
    keywords     = "real time planning, operations research, mathematical model, cancelled train line",
    booktitle    = "{IAROR} Hannover 2007",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/5264-full.html",
    abstract     = "{DSB} {S-}tog (S-tog) is the operator of the suburban rail of
Copenhagen, Denmark. The suburban network covers approximately 170
km of double-track and 80 stations. When larger disturbances occur
in the {S-}tog network one of the countermeasures is to take out
entire train lines. The problem is to decide when the reinsertion
shall start on each rolling stock depot in order to resume
scheduled service. As the process of resuming service is regulated
by a number of constraints, the task of calculating a reinsertion
plan of a train line becomes complex. Here we present a mixed
integer programming (MIP) model for finding a reinsertion plan of
a train line minimizing the latest time to  reinsertion. The {MIP} 
model has been implemented in {GAMS} and solved with Cplex. The
optimal solution is found within an average of 0.5 {CPU} seconds in
each test case. Reinsertion plans in operation is today calculated
by the reinsertion model."
}