Lean manufacturing a trend that has come back

In today's tighter economy certain trends that were once put by the wayside have come to back to the forefront of manufacturing.One of these trends is lean manufacturing. In a manufacturing environment that must know produce under tightening costs lean manufacturing is once again moving to the top of many companies production methods.

Lean manufacturing or lean production, which is often known simply as "Lean", is a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus it becomes a target for elimination. The idea is that working from the perspective of the customer who consumes a product or service, "value" is defined as any action or process that a customer would be willing to pay for.

Basically, Lean is centered on creating more value with much less work. Lean manufacturing is considered to be a generic process management philosophy derived mostly from the Toyota Production System (TPS) (the term Toyotism is also prevalent) and identified as "Lean" only in the 1990s.The process is renowned for its focus on reduction of the original Toyota seven wastes in order to improve overall customer value, but there are varying perspectives on how this is best achieved. The steady growth of Toyota, (from a small company to the world's largest automaker) has focused worldwide attention on how it has achieved this.

Lean manufacturing is also a variation on the theme of efficiency that is based on optimizing flow.It is considered to be a present-day instance of the recurring theme in human history toward increasing efficiency, decreasing waste, and using empirical methods to decide what matters, rather than uncritically accepting pre-existing ideas. Lean manufacturing is often seen as a more highly refined version of earlier efficiency efforts that builds upon the work of earlier leaders such as Taylor or Ford, and learning from their mistakes.

Lean principles originated from the Japanese manufacturing industry. For many, Lean is considered to be the set of "tools" that assist in the identification and steady elimination of waste. The theory being that as waste is eliminated quality then improves while production time and cost are reduced. Examples of such "tools" are the Value Stream Mapping, Five S, Kanban (pull systems), and poka-yoke (error-proofing).

There is also a second approach to Lean Manufacturing, which is promoted by Toyota, in which the focus is upon improving the "flow" or smoothness of work, thereby steadily eliminating mura ("unevenness") through the system and lessoning the focus upon "waste reduction". Techniques to improve production flow include production leveling and "pull" production. This is a fundamentally different approach to most improvement methodologies.

The difference between these two approaches is not the goal itself, but rather the approach to achieving it. Proponents of the process feel that the implementation of smooth flow exposes quality problems that already existed, and thus waste reduction naturally happens as a consequence. The advantage that is claimed for this approach is that it naturally takes a system-wide perspective, whereas a waste focus sometimes wrongly assumes this perspective.

The overall principles of Lean include: Pull processing, Perfect first-time quality, Waste minimization, Continuous improvement, Flexibility, Building and maintaining a long term relationship with suppliers, Automation, Load leveling and Production flow and Visual control.

The disconnected nature of some of these principles may spring from the fact that the Lean has grown sporadically since 1948 as it responded to the problems it saw within production facilities. Thus what one sees today in viewing Lean is the result of a "need" driven learning to improve where each step has built on previous ideas and not something based upon a theoretical framework.