Lean Manufacturing (also known as Lean Management, Lean Enterprise, Lean Production, Lean Thinking – they are all names for the same thing) is a system of management developed by the Toyota Motor Corporation and adapted successfully across the world to almost every sector of manufacturing as well as a huge range of non-manufacturing sectors including Healthcare, Banking, Government and Services.

So What is Lean Manufacturing and how did it come about?

Back in the 1980’s when western companies realised that they were rapidly losing market share to Japanese manufacturers, a number of US and European academics were sent to study the differences between Toyota and the US and European manufacturers, (most famously Womack and Jones ) From these studies the term lean manufacturing was coined to describe Toyota’s relentless focus on eliminating waste and lead time.

Lean manufacturing, or the Toyota Production System, is in fact a very practical solution developed by a medium sized manufacturer to address its cash flow problems. While many manufacturers may be daunted by the size of automotive assembly plants and see them as a unique working environment that has little in common with their business, the reality is that the underlying principles of lean manufacturing are simple, common sense and can be applied in every manufacturing business, no matter how small.

So, what are those underlying principles?

VALUE AND WASTE

As I mentioned, Toyota realised that most of what happened in their factories did not add value to the product and therefore was waste. It classified this waste into seven categories. In recent years others have added more waste categories, but I think the original seven is a good place to start.

THESE SEVEN WASTES ARE:

1 INVENTORY
2 WAITING TIME
3 MOTION
4 TRANSPORTATION
5 DEFECTS
6 OVER-PROCESSING
7 OVER-PRODUCTION

 

The Four Rules of the Toyota Production System

Many businesses over the past 30 years have experimented with the tools of lean manufacturing. Most of you have heard of methods such as 5S, Kanban, single minute exchange of die (SMED), and total productive maintenance (TPM).

Despite implementing these tools, many companies did not see the improvements in performance they expected. Further study of the Toyota Production System revealed some basic principles that supported it. These were described in 1999 in an excellent Harvard Business Review article by Stephen Spear and Kent Bowen. Spear and Bowen identified four rules which were integral to everything Toyota did. Again, these rules are simple, practical, and applicable to every manufacturing business. They are essentially the basic principles that Toyota (and other lean companies) apply to eliminate the eight wastes.

THE FOUR RULES ARE:

RULE 1:
All work is specified in terms of content, sequence, timing, and outcome.
RULE 2:
Every customer-supplier connection must be direct and there must be an unambiguous yes-or-no way to send requests and receive responses in the supply chain.
RULE 3:
The pathway for every product or service is simple and direct.
RULE 4:
Improvements are made using a scientific method under the guidance of a teacher, at the lowest possible level of an organisation.

 

References
Roos, Daniel, Ph.D.; Womack, James P., Ph.D.; Jones, Daniel T. 1991. The Machine That Changed the World : The Story of Lean Production, Harper Perennial
Spear, S. and Bowen, H.K. Decoding the DNA of the Toyota Production System, Harvard Business Review, September-October 1999.