Definition of LEAN Manufacturing : 5S, Kanban, MUDA

LEAN is a business strategy that delivers products and services that meet customer expectations, when the customer wants them, in the number required, at the right price, using the minimum of materials, equipment, space, work and time. The most critical situations and their consequences can be experienced: interruption of a line due to lack of supply of a part, stock shortage.... No customer, if he knew, would agree to pay the extra cost of the products and/or services he purchases to compensate for the inefficiency of his supplier. It is not the supplier who will reveal his own inefficiency, but the competitors, by proposing better products, at more interesting costs and delays.

LEAN therefore means less waste, shorter cycle times, fewer suppliers, less bureaucracy, but LEAN also means more competent employees, more delegation, a more agile and efficient organisation, more productivity, more satisfied customers and more long-term success.

LEAN is the result of Lead Time and Takt Time

Initially developed by Toyota, LEAN, literally "thin", "thin", links performance (productivity, quality) to the flexibility of a company, which must be able to constantly reconfigure all its processes (industrial responsiveness). LEAN advocates seek performance through continuous improvement and elimination of waste, MUDA in Japanese. In order to obtain this performance, LEAN is based on two main parameters. First of all the lead time, corresponding to the time needed to carry out all the operations from the acceptance of the order until its dispatch. Finally, Takt Time, representing the reflection of ideal consumption by customers. Takt Time is the rate at which we want a unit to leave the company's manufacturing process.

LEAN Thinking, continuous improvement of activities

Since the 1950s, Toyota's Production System (TPS) has constantly evolved and the principles of this method were published in a book written by J.P WOMACK and D.T JONES in 1997 under the title "LEAN THINKING" (Philosophy or way of thinking). LEAN Thinking, or the adoption of this way of thinking, makes it possible to leave the purely curative framework of the hunt for waste and the improvement of performance and to apply its principles preventively, during the development of products, processes, activities...

Flooded with problems of all kinds (relocations, saturated markets, increase in materials, technological innovations, etc.), most managers are looking for solutions (turnkey), kits to meet their most pressing problems. However one of the most burning is the operational competitiveness of French companies, as highlighted in a recent report by Mc KINSEY. In times of crisis, to continue to perform well, the company must adapt its activity quickly to a tense environment without systematically resorting to investment.

Today, LEAN Manufacturing is an organizational model that improves the company's flexibility and responsiveness so that it can be more competitive with more respondents to customers who pay close attention to these two aspects.

• Objective of the LEAN Manufacturing method on quality

  The increase in the quality level of the work process translates into a reduction in the number of errors, retouching and rejects. This reduces the use of the company's resources and therefore the total cost of operations.

• Objective of the LEAN Manufacturing method on cost

  At the entrance of a production plant, we find the human resources, the installations, the raw materials and at the exit, we find the finished products. Productivity increases when identical input resources generate more finished products at output, or when the volume of identical finished products decreases input factors.

• Objective of the LEAN Manufacturing method on lead times

  Reduce execution time: time is defined as the time interval between the receipt of raw materials and the receipt by the company of payment for the products sold. Reducing this interval means more products manufactured at the same time, better resource rotation and greater responsiveness and flexibility to meet customer needs.

The strength of the continuous improvement approach

The LEAN approach is broader than a simple production method, and forms a coherent system of complex concepts, articulated to an original practice and to specific means of formalisation and appropriation. LEAN proponents apply themselves to teaching it, applying it and spreading its rules within the industrial community. Each element has its place and function within a structured organization. Actions cannot be carried out without having proven working tools and a structured organisation. The best illustration of the SOLIDITY of such an approach consists in considering the company under the aspect of a monument capable of resisting the assaults of time.

Stability is the foundation of the monument. LEAN Manufacturing can only grow if this solid foundation is built first. Applied to the organization, we talk about team stability, standardization of methods, strategy followed over time... The slab on which everything else is built, consists of 2 elements the Kaizen or continuous improvement and the reduction of MUDA or waste both set the system in motion. The 2 columns of the JIT, meaning just-in-time and JIDOKA monument rest on 2 bases, the HEIJUNKA and the TRAVAIL STANDARD, a system designed to absorb as much as possible the jolts of demand.

JIT column tools are continuous flow production, pull flow, TAKT TIME and rapid tool change (SMED), JIDOKA column tools are man-machine separation (one operator manages several machines) and autonomation : stand-alone machines detecting their own errors, poka-yoke methods, problem analysis (5 why). The roof, or objective of the LEAN Manufacturing method, is summarized by QCD, quality improvement, optimization of production costs, adaptation of lead times to the real needs of the customer. A house cannot be consolidated if only one pillar is built. This is also true for LEAN.