Part 3: Seven Forms of Waste
By Ron Ketterling, President BASM
In continuation of our series on Lean Manufacturing processes, one of the primary focuses is on reducing waste, which can come from seven areas including: transportation, inventory, wasted motions, waiting, over-production, over-processing, and defects. Here is a tip to help remember these seven wastes – use the acronym Tim Wood – look back at the bold letters to see what it means.
1. Transportation waste occurs when materials are moved from one place to another. This type of waste is caused by the inefficient layout of machines and factories. For instance, any time a pallet jack, forklift or truck is used to move product from one location to another, this is classified as transportation waste. The result is non-value-added time between value added processes.
2. Raw material, work in process, and standing inventory are all non-value-added, and therefore, have the potential to create inventory waste. Excess inventory is the result of overproduction and it actually hides and even creates other forms of waste. For instance, space is wasted when stock rooms are filled with finished goods. And, although having a full inventory can give a sense of security, your cash is tied up in your stock. However, reducing your inventory waste is the best gauge of a lean transformation.
3. Any movement of a person’s body that does not add value is wasted motion. Excess motion, such as extraneous lifting, walking or reaching can result in fatigue, injuries, wasted time and frustration. A simple visual tool called a Spaghetti Map outlines the flow and pathways taken by people and materials throughout a facility, often resembling cooked spaghetti, hence the name. Spaghetti Maps can help a company reduce its wasted motion by quantifying distances traveled, in addition to helping identify the bottlenecks, poor layout and workarounds and inefficiencies in the process.
4. Waiting occurs when a person or machine must wait to do needed work. Typically, 99% of a product’s time is spent waiting. This waste also occurs when a worker watches a machine run automatically. Not only does waiting reduce productivity, it interrupts the flow of materials through the value stream. Additionally, waiting increases lead time, negatively impacts delivery performance and adds expediting costs.
5. Companies will overproduce a product before the customer wants it – or – produce more product than the customer ordered. Consequently, overproduction adds lead time, reduces productivity and hides other waste forms. Furthermore, it enables defects and causes scrap and must be eliminated to implement lean processes.
6. Processing waste is an operation that the customer does not pay for. This can include an extra operation to hold an unnecessary tolerance or to rework defective parts. “Just in case” operations, because customer needs are not truly understood, are also an example of processing waste. Moreover, over-automation, which drives overproduction, is another way a company creates processing waste.
7. Defects result in scrap or rework and have the serious potential to lead to compromised customer expectations and poor delivery and productivity. Defects actually affect all of the other forms of waste and are often the result of not matching the process to the need.
Understanding the causes of waste will likely help you identify ways to minimize it. Our goal is not to be lean manufacturing experts, but to help you maximize your automation systems. By understanding the principles behind lean manufacturing, together we can help your company refine processes so you can be better at what you do, and ultimately, do it in a more profitable manner.