Comparison of MRPII, JIT and OPT

1、Comparison of MRPII, JIT and OPTAlan WaltersScope MRPII Concerned with converting customer orders into time-phased requirements JIT Concerned with product and method of manufacture; also supplier relationships OPT Is a scheduling toolApplication MRPII Batch systems; large product variety; demand mix

2、ture of orders and forecast; make to stock environment JIT Mass and repetitive production systems; assemble to order environment OPT Batch systems; large product variety; demand mixture of order and forecastBasic theory and Weaknesses - MRPII Dependent demand items BOM explosion creates necessary re

3、quirements Hierarchical planning system Co-ordination through database Stresses role of planner Does not address design of process Complicated Capacity management tends to swamp user with detail Is too large some areas becoming redundant Batches need to be split Use of average lead timesBasic Theory

4、 and Weaknesses - JIT Pursuit of manufacturing excellence Ideals seen as challenges Long term commitment Kanban only part of total system Concerned with engineering manufacturing process rather than planning production Mixing of products without batches Decentralise control to operator Development of flexible resources Limited in application May be problems with supply chainBasic Theory and Weaknesses - OPT Teaches usefulness of finite scheduling CCR recognition and discrimination between management of CCR and non CCR operations Is a proprietary