The design of a 0–1 integer optimizer and its application in the Carmen system

We describe the design of an optimizer for 0–1 integer programming aimed at solving large problems. The algorithm is based on very simple operations giving it a low complexity, and we show that for large set covering problems it can produce very good solutions compared with other methods. This is the only optimizer in the Carmen system for airline crew scheduling, used by several major European airlines, and we discuss how it has affected the overall design and success of this system.