IMPROVED IMPLICIT OPTIMAL MODELING OF THE LABOR SHIFT SCHEDULING PROBLEM

This paper presents an integer programming model for developing optima l shift schedules while allowing extensive flexibility in terms of alt ernate shift starting times, shift lengths, and break placement. The m odel combines the work of Moondra (1976) and Bechtold and Jacobs (1990 ) by implicitly matching meal breaks to implicitly represented shifts. Moreover, the new model extends the work of these authors to enable t he scheduling of overtime and the scheduling of rest breaks. We compar e the new model to Bechtold and Jacobs' model over a diverse set of 58 8 test problems. The new model generates optimal solutions more rapidl y, solves problems with more shift alternatives, and does not generate schedules violating the operative restrictions on break timing.