Sequencing and scheduling is a formof decision-making that plays a crucial role in manufacturing and service industries. In the current competitive environment effective sequencing and scheduling has become a necessity for survival in the market-place. Companies have to meet shipping dates that have been committed to customers, as failure to do so may result in a significant loss of goodwill. They also have to schedule activities in such a way as to use the resources available in an efficient manner.
Scheduling began to be taken seriously in manufacturing at the beginning of this century with the work of Henry Gantt and other pioneers. However, it took many years for the first scheduling publications to appear in the industrial engineering and operations research literature. Some of the first publications appeared in Naval Research Logistics Quarterly in the early fifties and contained results by W.E. Smith, S.M. Johnson and J.R. Jackson. During the sixties a significant amount of work was done on dynamic programming and integer programming formulations of scheduling problems. After Richard Karp’s famous paper on complexity theory, the research in the seventies focused mainly on the complexity hierarchy of scheduling problems. In the eighties several different directions were pursued in academia and industry with an increasing amount of attention paid to stochastic scheduling problems. Also, as personal computers started to permeate manufacturing facilities, scheduling systems were being developed for the generation of usable schedules in practice. This systemdesign and development was, and is, being done by computer scientists, operations researchers and industrial engineers.