The Toyota Production System
Anyone that has worked with lean manufacturing and Six Sigma knows that the two processes share several different variables. It often poses the question, "should I implement one or two process improvement strategies?" While you can implement different tools from each system, it is best to pick one and then add on the additional tools as your company gets used to it.
Implementing two systems at the same time can be overwhelming for your managers and it can cause them to experience burnout. They won't have the time or the energy to keep up with the different controls and this can decrease employee morale.
The Toyota Production System
Lean manufacturing is a method to reduce waste while producing tangible goods. Lean manufacturing is also known as the Toyota Production System (TPS). TPS focuses on the elimination of waste and they define it in 3 ways, Muri, Mura, and Muda. For this article, we will focus on Muda and the 7 different types of waste.
- Over-production. Many companies manufacture an item before it is needed. This is considered a waste because it costs the company money and decreases the quality and productivity of the manufacturing process. Overproduction results in higher costs for storage, excessive lead times, and it makes detecting the defects quite difficult. The solution for overproduction is to stop producing materials and only produce what can be immediately sold or shipped.
- Waiting. Waiting refers to the waste of goods that are not moving. As you already may be aware, much of a product's life is spent waiting for the next phase. The reason this is considered a waste is because the good should never be waiting. If they are waiting it is due to poor material flow, long production runs, or travel distances.
- Transporting. Moving your product from one location adds no value to your product. Many products are damaged or lost, casing a waste of money. Transporting also requires the use of material handlers, and this also adds no value to the product. This is one waste that is difficult to reduce or eliminate. Mapping the flow of your product may be one way you can gain a greater understanding of the transportation phase and learn how to reduce the costs.
- Inappropriate Processing. Several companies purchase high precision equipment to do a simple job. High precision equipment often leads to over-production of goods.
- Unnecessary Inventory. Excessive inventory is a direct result of overproduction and waiting. Having excessive inventory will lead to increased lead times, limited floor space, and poor communication. Too much inventory often masks problems from other areas as well.
- Unnecessary / Excess Motion. This phase is often related to behavior-based safety. It is the unnecessary bending, stretching, walking, lifting and reaching of an employee. Often the motion is not due to the employees behavior, but the machine they are operating may be manufactured poorly and the employee is unable to turn a knob (or something similar) without using poor ergonomics. This waste leads to health and safety issues, which obviously lead to bigger problems.
- Defects. Defects in the manufacturing process are a tremendous cost to a company. Any small defect directly impacts your bottom line and effects inventory, scheduling, inspection, and other factors. A minor defect can cost your company more than the entire manufacturing cost to begin with.
The TPS is one of the most successful process improvement strategies. Since Toyota implemented it into their system, they saw their sales climb by 50% in 10 years. They are now one of the world top auto manufacturers with only General Motors providing them with legitimate competition.