What is Lean?
Lean (also known as Lean Production, Lean Enterprise, and Lean Thinking) involves a set of principles, practices and methods for designing, improving and managing processes. The development of Lean is attributed to Taiichi Ohno’s articulation of the Toyota Production System. Ohno aimed to improve efficiency by eliminating particular kinds of waste (called MUDA, in Japanese) which absorb time and resources but do not add value. Examples include mistakes which need rectification, unneeded process steps, movement of materials or people without a purpose, unnecessary waiting because upstream activity was not delivered on time, and the creation of goods or services that are not really needed by end users.
A Lean process reflects the goal of continually reducing waste and improving work flow to efficiently produce a product or service that is perceived to be of high value to those who use it. Implementation of Lean involves systematic process assessment and analysis. The preliminary stages of Lean assessment include “value stream mapping” in which key people, resources, activities and information flows required to deliver a product or service are made explicit and depicted graphically. The value stream map is a key tool for identifying opportunities to reduce waste and more tightly integrate process steps, thus improving process efficiency.
Improvement approaches such as Lean and Six Sigma grow out of a long tradition of quality and process improvement efforts in manufacturing. For example, Frederick Winslow Taylor’s scientific management and Frank Gilbreth’s “time and motion” studies were among the earliest prescriptions for improving the quality and efficiency of production processes. Current thinking about process improvement draws heavily on the ideas of W. Edwards Deming, Joseph Juran and other statisticians whose data analysis tools and management philosophies were initially adopted by Japanese manufacturers, and have come to be known as Total Quality Management (TQM) or Continuous Quality Improvement (CQI).