The cost of inflated planned lead times in MRP systems

摘要: Abstract Much of the current literature in field production and inventory control systems stresses need to revise traditional forms thinking regarding processes, role inventories for work process, reduced lead times or flow times. Group technology, manufacturing cells, other means incorporating repetitive techniques into job-shop settings constitute leading edge system development. Still, there is resistance these dramatic changes, “business as usual” methods still predominate. This study attempts illustrate graphically cost justification associated with reduction which generally results from new concepts. In most job shops today, are much longer than they be due inflation time estimates. Actual manufacture fabricated assembled products have been shown a direct consequence planning used MRP process—a form self-fulfilling prophesy. The research employs simulation model factory using tool multiproduct, multilevel environment. Manufacturing costs dependent variable experiments, defined sum material (including expedite premiums), labor overtime carrying costs, overhead costs. independent being manipulated planned offset process. Twenty values evaluated ranging value that includes no slack at all (pure assembly line) up allows 95% (queue) which, unfortunately, not uncommon many today. Stochastic variables include customer demand actual processing times—the set-up run result curve formed over range constructed nonlinear regression techniques. conclusions resultant graph clearly indicate consequences long times, exponential increases beyond 80–90% queue level. Total 41% higher maximum allowance compared minimum. Clearly, this demonstrates reduction, either through downward adjustment by introducing