The core philosophy of lean manufacturing is waste elimination. The focus is not quick or more production but, to eliminate waste of any kind which has no value addition. Companies by focusing and following the philosophy of “do it faster, do it better” hide the symptoms of problems which hamper quicker and better production. Lean manufacturing reduces costs and increase productivity by addressing the root of the problem by eliminating the “muda”.
Muda is a Japanese term meaning “waste” as, lean manufacturing is an Japanese management philosophy hence, Japanese terms and concepts are used extensively. There are 7 mudas or seven types of waste that are found in a manufacturing process which are
- Overproduction – An protective or “just in case” mindset usually results in overproduction. Producing more than the customer requires is waste. It causes other wastes like inventory costs, manpower and conveyance to deal with excess product, consumption of raw materials and installation of excess capacity.
- Needless Inventory – Inventory at any point is a no value-add as it ties up financial resources of the company and is exposed to the risk of damage, obsolescence, spoilage, and quality issues. It also needs space and other resources for proper management and tracking. Large inventories also cover up process deficiencies like equipment problems or poor work practices.
- Defects – Defects and broken equipment results in defective products and subsequently customer dissatisfaction, which need more resources for solving. Shipping damage is also taken as a defect. Any process, product, or service that fails to meet specifications is also a waste.
- Non-value Processing – It is also called over-processing, for which more resources are wasted in production, their wasted movement and time. Any processing that does not add value to the product is waste like in-process protective packaging. It is primarily due to extra or unnecessary manufacturing steps, using older and outdated methods or not having standard work plans.
- Excess Motion – Unnecessary motion which is also a waste occurs due to poor workflow, poor layout, housekeeping, inconsistent and undocumented work methods or lack of standardized procedures or even a deficiency in employee training. It is usually hidden as it’s not easily evident, but careful observation and worker’s communication can highlight it.
- Transport and Handling – It focus on shipping damage and includes pallets not being properly stretch wrapped (wasted material), or a truck is not loaded to use floor space efficiently or in handling, setting up or fixing a wrapping machine. Material should be shipped directly from the vendor to the location in the assembly line where it will be used also called as point-of-use-storage (POUS).
- Waiting – These are wastages in time, usually due to broken machinery, lack of trained staff, shortages of materials, inefficient planning, and waiting for material, information, equipment, tools, etc. It leads to slowed production, delayed shipments, and even missed deadlines.
There are other types of waste in other places which are
- Confusion – It is due to misinformation
- Underutilization of available employees (of their skills and knowledge ) and facilities Elimination of these wastes is discussed next though it can be a long and difficult task, but the results of improved productivity and profits are what it aims for.