Integrated procurement-production systems: A review

Traditionally, the economic lot size problem of raw materials and finished products is treated separately and this may result in suboptimization. On the other hand, the integrated procurement-production (IPP) systems offer unification of these subsystems and the decisions are taken in a coordinated manner. This paper attempts to review the literature on IPP systems. The literature has been classified and after identifying the critical gaps existing between theory and practice, some research directions are identified.