The core idea of lean manufacturing is actually quite simple…relentlessly work on eliminating waste from the manufacturing process.
So, what is waste? It can take many forms, but the basic idea is to eliminate anything and everything that does not add value from the perspective of your customer.
Another way to look at lean manufacturing is as a collection of tips, tools, and techniques (i.e. best practices) that have been proven effective for driving waste out of the manufacturing process.
Let’s talk a bit more about waste. Traditional lean identifies seven key areas of waste – typically referred to as the Seven Deadly Wastes. These are described below along with suggested countermeasures. Don’t worry if the countermeasures are not immediately “actionable” for you – right now they can be considered simply as a roadmap for the future.
What is Overproduction?
Making something before it is truly needed. This is a particularly serious form of waste because it leads to excess inventory that is often used to mask other underlying problems and inefficiencies.
What are Countermeasures for Overproduction?
- Pace production so the rate of manufacturing matches the rate of customer demand (Takt Time).
- Use a pull system to control how much is manufactured (Kanban).
- Reduce setup times so that smaller batches can be economically manufactured (SMED).
What is Waiting?
Time when work-in-process is waiting for the next step in production (no value is being added). It can be truly illuminating to look at the time from order to shipment and ask – how much of that time is actually spent on true value-added manufacturing.
What are Countermeasures for Waiting?
- Design processes so that the flow is continuous and there are minimal (or no) buffers between steps in production (Continuous Flow).
- Use standardized work instructions to ensure that a consistent method and consistent times are used for each step of production (Standardized Work).
What is Transport?
Unnecessary movement of raw materials, work-in-process or finished goods.
What are Countermeasures for Transport?
- Design a linear, sequential flow from raw materials to finished goods (Value Stream Mapping).
- Make sure work-in-process is not placed into inventory (Continuous Flow).
- Avoid continual changing of job priorities (Theory of Constraints).
What is Motion?
Unnecessary movement of people (movement that does not add value).
What are Countermeasures for Motion?
- Ensure that work areas are logically organized (5S).
- Consider alternate arrangements of equipment that reduce motion (Value Stream Mapping).
What is Overprocessing?
More processing than is needed to produce what the customer requires. This is often one of the more difficult wastes to detect and eliminate.
What are Countermeasures for Overprocessing?
- Compare customer requirements to manufacturing specifications (Kaizen).
- Look for potential simplifications to the manufacturing process (Kaizen).
What is Inventory?
Product (raw materials, work-in-process, or finished goods) quantities that go beyond supporting the immediate need.
What are Countermeasures for Inventory?
- Bring raw materials in only as they are needed (Just-In-Time).
- Reduce or eliminate buffers between steps in production (Continuous Flow).
- Refer to Overproduction countermeasures (Takt Time, Kanban, and SMED).
What are Defects?
Production that is scrap or requires rework.
What are Countermeasures for Defects?
- Design processes so they are less likely to produce defects (Poka-Yoke).
- Design processes to detect abnormalities so they can be immediately corrected (Jidoka).
- Look for the single most frequent defect and determine why it occurs (Root Cause Analysis).
- Create work instructions that provide a consistent method of manufacturing the part. (Standardized Work).
Lean concepts become a lot more intuitive and easy-to-understand when they are traced to the ultimate goal – eliminating waste.
An extremely important form of waste that is not represented within the Seven Deadly Wastes is unused human potential. This form of waste results in all sorts of lost opportunities (e.g. lost motivation, lost creativity, and lost ideas).
One of the reasons that this from of waste is often underemphasized or even ignored at companies is that responsibility for it lies squarely on the shoulders of management. Unused human potential often results from management policies and management styles that diminish employee contributions. By way of contrast, developing strong coaching skills for managers can be very effective in strengthening employee contributions.