Lean when Based on Toyota Production System Fails for High-Mix Manufacturers

The 2007-05-02 issue of USA Today features an article titled “Toyota’s success pleases proponents of lean”. The popularity of lean manufacturing today has come almost entirely from Toyota’s success. http://www.usatoday.com/money/autos/2007-05-02-toyota-lean-usat_N.htm

However, the article goes on to state that a survey by management consulting firm Bain shows that only 19% of companies that have tried lean are happy with it. While there are a number of barriers to success in using lean, one clear problem is that the challenges faced by high-mix manufacturing are not adequately addressed by low-mix techniques of Toyota-based lean approaches.

The buzzword lean often encapsulates cellular, group technology, balancing capacity, load leveling, kanban and tact time concepts. These concepts will not and cannot deliver value to high-mix manufacturers excepting setup-time reduction, kanban and 5S (i.e., orderliness and cleanliness). For high-mix manufacturers, it is likely that few of these companies that have tried Toyota Production System–based Lean (Lean-TPS) are happy with it. When the concepts are implemented, they are often weak approximations of Lean-TPS or true implementation is impossible to achieve at all. Most of the problem emanates from highly volatile incoming order dynamics unique to high-mix manufacturing.

The fundamental operational dynamics for high-mix manufacturing requires a different approach that TPS-Lean is ill equipped to address. In the original translation of the book, “Toyota Production System from Industrial Engineering Viewpoint”, it states that the TPS Kanban system, “…could only be adapted only in the case of ‘repetitive production’ and impossible to utilize for individual production.”

For high-mix manufacturing, a systems-based approach is essential. 21st century state-of-the-art manufacturing techniques are based on the science called holonics. Holonics is a systems-based approach which provides stability in the face of disturbances, delivers adaptability and flexibility in the face of change while maintaining efficiency, and facilitates agility.

Each of the key areas of manufacturing is approached within the overall holonics systems architecture approach. A complete understanding of MRP and its proper setup and use is fundamental to attaining a lean inventory position. Capacity planning and synchronized scheduling methodology enables efficiency and high throughput. Tactical alignment with strategic goals is a must for achieving superior levels of responsiveness and delivery performance.

The high-mix, low volume environment benefits from a holonics architecture rather than a TPS-Lean model. Proper modeling of the overall organizational architecture coupled with an operational model and communications strategy and tactics is the recipe for attaining competitive advantage. Holonics delivers that competitive advantage today for high-mix manufacturers.

R. Michael Mahoney