All entries for Sunday 08 March 2009
March 08, 2009
Today I came across reading a book on Lean production "The Machine that changed the world" James P. Womack, Daniel T. Jones and Daniel Roos; 1990; Macmillan. I got this book initially to read about supply chain management but realised this is actually a book about Lean production of Toyota.
I recommend this book because
- I believe it is one of the first texts on lean, according to the book the authors coined the term lean
- It is easy to read. It begins with a history of automobile manufacturing from craft production to mass production which has ills and inefficiencies that eventually give rise to Japan's lean production. The clear logical flow allow you to see why lean become important. What I find most useful is it clearly contrast the management philosophies between the West and Japan
Mass Production Lean Production Produce everything in mass leads to inventories Produce only what is needed, aim for zero inventory Kanban system Market style relationship with supply chain Seek long term relationship with suppliers Clear separation of design with production Provide suppliers only with performance specs, but allow supplier to come up with product specs Tolerance mentality toward defect, defect is seen as 'inherent' and cannot be eliminated '5 why's' problem solving system (similar to root cause analysis). root cause of defect is eliminated and will never happen again Firefighting or 'fix it' mentality toward problems Kaizen gradual improvements invovling small teams and devote time to reflect and solve problems
One of the amazing idea I find is
In Western style assembly line, management promote maximum throughput and allow no stoppage in assembly line. So line managers have no incentive to fix minor problems because his ass is on the line if assembly stops. This result in small problems snow-balling into big problem in end product, and within production process.
Lean production devolve responsibility down to floor worker, any worker is free to stop assembly line if a problem is discovered, and group of workers will work on solving problem together.
Not surprisingly, when each worker is free to halt the process, the assembly proces actually almost never stops because the process defects has been eliminated. Whereas to impose non-stop assembly always end up stopping the assembly because of various small problems during production. And the end product often has many defect which needs to be checked and fixed, incurring significant cost on repair and quality checks.
- Detailed description of lean and how it relate to production, supply chain, customer and so on. Page 55-57 describes lean principles in assembly line which resembles six sigma (teamwork, quality circle, root cause)
Verdict: Even though I have only spent a couple hours reading this book, I can already grasp the keys ideas about lean (compare this to some books you read for hours but still have no idea what the topic is about?). This text is filled with rich examples from Toyota company and is very easy to read. I'd recommend this to people studying lean for PIUSS or for their project, if they havnt already come across it.