Lean ENgineering and Waste Elimination

Published: 25th January 2010
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The 5-S philosophy is associated with lean thinking. The objective of lean thinking is to provide a business with long-term profitability by developing a more effective workplace, which is accomplished by eliminating waste in the work environment. The result is a safer workplace, improved product quality, and lower costs for both the business and its customers.

Lean thinking may result in a reduction in work force, but that is not its purpose. In fact, the application of lean thinking for the purpose of reducing the work force is not lean thinking at all. Since some companies have done this, lean thinking has been given a bad reputation and has made waste reduction efforts more difficult.

The 5-S approach involves five activities in the workplace: scrapping, sorting, scrubbing, standardizing, and sustaining. Depending upon which book you read, there may be different names for each S, but the intent is the same.

Scrapping means to throw away unneeded material. A trashy work environment, in addition to being unsafe, tends to create a casual attitude toward quality. There should be a strategy for knowing what to keep and what to throw away. Take junk mail for example. It should only be handled once. Look at it, decide to use it or throw it away, and then take the appropriate action. When junk mail is handled more than once, it piles up on your desk making normal productive work more difficult. The same thing happens in a shop with trash and old parts, and in a store with boxes and packing material.

Sorting is the process of placing everything where it belongs. Imagine a toolbox where the drill bits are scattered throughout. If a bit is needed, it will take some time to find the bit. This adds time and cost to work. Now imagine a toolbox with the drill bits organized in a labeled drawer and separated logically by size. The time necessary to find the needed bit and get the job done is shortened, and the cost of the work is reduced.

Scrubbing the work environment involves cleaning the work area. A clean work area is safer than a dirty one and is conducive to higher quality work. It is related to discarding scrap but goes further by including the cleaning up of what is left. Consider a machine shop where cutting oil is left on the floor. This becomes a slipping hazard and indicates sloppiness. If you were inspecting machine shops to see which one to hire, what would you think about the shop with an oil mess on the floor?

Another example of the importance of scrubbing is preventative maintenance. In a manufacturing facility, for example, the machining equipment can be painted white and wiped down each shift with white cloths. It becomes easy to see any unusual oil leaks or dirt. This allows the factory workers to diagnose machine problems before breakdowns occur. The result is reduced cost.

Standardization is about making sure that important elements of a process are performed consistently and in the safest and best possible way. Lack of consistency will cause a process to generate defects and compromise safety. The standardization of work practices increases predictability. Predictability, in turn, allows the process owners and operators to prevent problems before they affect the customer.

Sustain means to maintain the gains. The 5-S philosophy will only work if it is consistently applied everywhere and all the time. By maintaining consistency, not only will gains be maintained, but there will also be improvement throughout the organization as the 5-S philosophy permeates the work environment. Eventually the philosophy becomes a part of the business' culture.

Finding and eliminating waste within a process or business is about mutual respect and trust, empowerment and accountability. Without these, waste elimination is impossible. As the eight types of waste are covered below, consider how mutual respect and trust, empowerment and accountability would be keys to success.

Elimination of Waste

Waste is any action that does not add value to the product or service in the eyes of the customer. This is related to process mapping, where there are value-added and non-value-added steps in a process. Different organizations may have different categories of waste than those listed below.

The Waste of Overproduction
The waste of overproduction is simply making more of a product or service than the customer demands. Overproduced goods have to be stored and are subject to obsolescence or spoilage. In the long run, overproduction results in higher wastage and cost. It is not important that every employee be busy in the production of goods and services, especially during slow times. Rather than overproduction, a better use of employee time would be maintenance or improvement activities.

The Waste of Over Processing
The waste of over processing is doing more than is required or desired by the customer. An example might be the addition of a "just in case" quality inspection at the end of a process when the data indicates that it is not needed. The customer pays for that unneeded inspection step. Another example is the need of multiple approval signatures for an activity when only one signature will do. This creates time delays and increases cost.

The Waste of Waiting
The waste of waiting manifests itself in many ways. A bottleneck in a process causes the waste of idle time in the next process step and back ups in the previous process step. Long checkout times cause the waste of waiting for the customer. Labor cost, lost customers, and expediting are examples of increases in costs associated with waiting.

The Waste of Correction
The waste of correction is associated with not doing a job right the first time. In process mapping the phenomena of hidden factories are discovered. They are the result of mistakes made in the process that must be corrected. The customer winds up paying for the wasted materials and time.

The Waste of transportation
Transportation waste is centered on the physical movement of goods and materials. Common causes of transportation waste are partially full containers, off-site warehousing, and multiple handling of material. An example would be a coal-fired power plant that is built a long way from the nearest coal. They will always have a large fuel transportation cost. Another example would be an inefficient layout of process functions. Consider an assembly line where components must be moved from place to place for assembly as opposed to an assembly line where a component is finished at the location where it is needed next.

The Waste of Motion
This is the waste of the unnecessary movement of people around a process. Examples are walking excessive distances, excessive repetitive actions, and excessive spread of resources within a process. An example might be having one fax machine in a five-story building.

The Waste of Inventory
This is similar to the waste of overproduction, but specifically addresses inventory within the process. For example, process step A produces twice as many components as needed for process step B. The excess must be moved or stored (waste of transportation). What would be the impact on operating cost if the process were changed the next day, making the stored "in process" inventory obsolete?

Another waste of inventory would be running out of a needed assembly component, thus shutting down a production line. Similar to this would be a store running out of an item that is selling well. In either case, opportunity is lost. Lost income (sales) is also a form of waste.

The Waste of Resources
This is the wasteful deployment of resources. This could be human or material resources. An example would be using an untrained person to do a job, which results in rework, which is a waste of both employees' time. Another would be the purchase of raw materials in excess of demand, which must then be stored. The business now has cash assets (wasted) tied up in stored material that cannot be easily liquidated.

A process improvement project should focus on the elimination or minimization of all causes of waste. In order to do this, process owners must be involved. These individuals are the most knowledgeable about where waste occurs in a process. Every mind that becomes involved in this endeavor adds to probability of success for the improvement team. More minds equal more ideas. In addition, the process owners will be changing their own process. Do not underestimate the power of synergistic thinking.

Lastly, waste reduction is a daily activity and not a project activity. It should be built into the planned process changes proposed by the improvement team so that gains in process performance are maintained. A process improvement project affects the culture of an organization, and because waste reduction is a cultural activity, they go hand in hand.

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