5S - Eliminating the Seven Wastes

Written by Steve Stephenson

One of the major benefits of 5S is that it helps address the seven wastes. These are seven waste categories that have been identified as commonly not adding value to a product. Identifying and eliminating waste in these seven waste categories improves overall efficiency and productivity.

However, before plunging into using 5S to eliminate waste in these seven categories you need to develop an eye for spotting waste. "Shigeo Shingo, a co-developer of TPS, observed that it's only the last turn of a bolt that tightens it - the rest is just movement (see waste #3 below). This level of refined 'seeing' of waste enabled him to cut car body die changeover time to less than 3% of its duration in the 1950s as of 2010." (1)

Using 5S To See Waste

"Seeing" all of the waste most often involves multiple steps. That's why 5S is ongoing, meaning that it is not just a one-time process of going through the five steps of 5S. Once 5S has been completed, go back and start the process again. Those things that were addressed the first time through the 5S process have been cleared away allowing you so see waste that was not noticed before.

What Are The Seven Wastes?

The seven categories where you need to look for waste are:

1. Transportation
2. Inventory
3. Motion
4. Waiting
5. Over-processing
6. Over-production
7. Defects

1) Transportation

The term "transportation" is used here to mean handling and moving materials or people during the production process. Moving materials around does not add value for the customer and it increases the risk of damage, incorrectly routed items, lost items, and delays affecting other parts of the production process. In addition there is a direct cost associated with transportation, as well as transaction costs related to transportation. These do not add value for the customer.

However, it is necessary to move materials during production, so "transportation" can never be 100% eliminated. The goal is to use 5S principles to reduce the transportation of products, supplies, tools and people as much as possible. The costs of any remaining transportation must be more than offset by a benefit resulting from the use of transportation.

2) Inventory

What is inventory?

Inventory is not just product in a warehouse. Inventory is any material that has been purchased and that has not yet produced income. Inventory includes finished products and raw materials, as well as work-in-progress.

Excess inventory results in higher facility costs to provide storage areas for the inventory. It may mean clutter and safety hazards because of unused materials stored in work areas. The cost of excess inventory is wasted capital.

Apply 5S practices to identify waste in inventory. Using 5S to clean up and get organized will help to reveal and eliminate inventory related waste.

3) Motion

In this context the word "motion" refers to the wear and tear on both machines and people as a result of motion. Transportation includes waste resulting from moving products. Motion causes waste in the people and machines used to produce the product.

For example, when motion in a machine is eliminated, wear parts are being eliminated. This reduces the need for lubrication. It reduces maintenance costs. You'll be reducing the likelihood of accidents and machine down time.

Movement that workers need to do can result in repetitive stress injuries. Unnecessary motion such as lifting, walking, reaching, twisting or turning can lead to wasted time, fatigue, health problems and safety issues.

5S can be used to reduce motion by organizing the workplace so that all needed tools and equipment are stored close to where they are needed. 5S eliminates clutter, organizes work areas more efficiently, and produces standardization, all of which can help reduce motion.

4) Waiting

Work that is in progress always has points at which nothing is happening. This is waiting time and is waste that can be eliminated. Waiting time requires space to hold the items or materials that are waiting, and there is a cost for this. Waiting may require items be handled multiple times, and there is a cost for this. Waiting in one area may be slowing down production in another area.

The cost (waste) created by waiting is easy to see in workers. If workers need to wait for materials, tools, supplies or authorization, that is wasted time. However, keep in mind that people are not machines. In some cases waiting can be valuable rest time that is needed to maximize productivity and quality.

5) Over-processing

Over-processing is defined as doing more work than necessary to produce a product. For example, machining a part to a greater precision than required by the customer would be over-processing. Having more people than necessary check drawings or inspect the work would be over-processing. If there are steps in the production process that can be eliminated, without reducing the value to the customer, they should be eliminated. If more precise equipment, more complex processes, or greater skills than are needed are being used, then there is waste that can be eliminated.

6) Over-production

When more product than is needed is produced, there is waste. Over-production results in:

• Higher inventory costs
• Losses due to deterioration or damage to the product while it is stored
• Defects are harder to spot and more defective items are produced
• Product becomes out-dated while it is in inventory

Over-production is the waste that deserves particular attention because it hides or leads to all of the six other wastes. When over-production is addressed, then wastes in other areas become apparent and can be reduced or eliminated.

7) Defects

Defects are waste. When there is a defect it either must be repaired or thrown out. If the defect reaches the customer there are additional costs for service, support, transportation, loss of good will and damage to your brand image.

Defects also have indirect costs and impact other products. They can result in changed production schedules, inventory bottlenecks, delays in engineering or design, and the inability to inspect other products because the QA focus is on the product with the defect.

5S And The Seven Wastes

5S is one of several tools you should use to help eliminate waste in these seven categories. By cleaning up, getting organized and implementing standards you will eliminate waste and remove barriers to seeing other areas of waste. Combine 5S with other lean tools such as kaizen and you'll have a powerful program for eliminating waste in all seven categories.

(1) Quoted from Wikipedia: http://en.wikipedia.org/wiki/Muda_(Japanese_term)