IENG 451 Lean Production System

Lean Production Do it better, do it faster, do it cheaper Old System – Price = cost + profit New System – Price (fixed) – cost = profit Key to Profitability is to cost reduction Key to cost reduction is employee involvement

Systems A system is an integrated series of parts working together to achieve a goal Consider the best of the best

System Mental Model Conventional Model Move the material Make as much as you can (push) Large batches Engineers/managers make standards Lean Model Stop production so that production never has to stop Make only what the customer wants (pull) Small batches People closest to work make standards Make problems visible

Lean Gurus Ohno – conceived Toyota lean production system Hiroyuki Hirano – 5S system Seiichi Makajima – total productive maintenance Kenichi Sekine – continuous flow Shigeo Shingo – jidoka, single-minute exchange of dies (SMED)

Lean System Goal Customer Focus High quality, low cost, short lead time Just-in-timeJidoka Standardization Stability Employee Involvement

Muda Waste or any activity consumers are not willing to pay Human motion – Actual work – Auxiliary work – Muda

Forms of Muda Delay – waiting for parts, waiting for a machine, waiting for operator Conveyance – large scale waste caused by inefficient layout, making large batches Correction – making and having to fix defective parts Over processing – design requirements that have little to do with customer desires; Porsche, NISH

Forms of Muda Inventory – carrying excess WIP, usually happens in a push system such as MRP Over production – making things that don’t sell; e.g.; big belt buckles, Ertl toys Knowledge Disconnection – disconnects within a company or between a company and a supplier; disconnects at SDSMT?

Muda Lengthens Throughput Time Motion Waiting Conveyance Correction Over Processing Over Production Inventory Disconnects