“Lean” is a term that was coined in the late 1980s based on a study of the Toyota production system. It is based on the concept of continuous improvement of both the process and the product, while eliminating non-value added aspects of the process. Focusing on the value added parts of the process, a set of principles and tools for reducing waste (“muda”) in production process was developed. Lean also identifies the waste created by overburden (“muri”) and uneven flow (“mura”). Improving the “flow” creates a more efficient process. By creating better flow, problems surface, and waste is eliminated by eliminating inefficiencies. Eliminating waste and creating efficient ...view middle of the document...
Large inventories are their own type of waste. Not only are the cost of materials and labor tied up in the inventory, but there is cost associated with storing, pulling and shipping the products, and the products may be damaged while waiting to be shipped.
Using inappropriate equipment or techniques, or performing processes that are not required by the customer, costs money and time.
5. Unnecessary motion
Movement of machines and employees should be set up to be as efficient and ergo metric as possible. It takes time and energy to move between workstations and machines, if it is not properly set up, injury to employees or products can result.
6. Unnecessary transport
Moving products from one place to another adds no value and increases the risk of damaging the product. In addition, if equipment is required to move the products, there is a cost associated with operating that equipment.
There are many causes of waiting, incomplete or misinformation, interruptions, the preceding process time is not coordinated and completion of a supporting function. This disrupts the flow, so is one of the more serious wastes.
Sometimes two additional wastes are identified, the waste of producing goods or services that do not meet customer demands or specifications and the waste of human talent or skills.
Many tools have been developed to identify and work toward elimination of waste. Here are some examples:
This system is named for five Japanese words that have been translated into five English words with similar meanings: sort, systematic, shine, standardize and sustain.
Sort – get rid of unnecessary or unwanted materials and remove everything that is not in use.
Systematic – arrange so that items are easy to find and select.
Shine – thoroughly clean the work area and inspect equipment.
Standardize – establish order and maintain it.
Sustain – keep everything in order and perform regular audits.
2. Value stream mapping
Value stream mapping is used to map the current state of a process and identify where there is touch time and wait time and develop a more ideal future state that eliminates the non-value added parts of the process.
3. Standardized work
There are three main elements to standardized work. "Takt" time, the time that it takes to produce a product to meet customer demand; work sequence is how the work must be performed within the takt time and standard inventory is the materials and machine time required to keep the process flowing smoothly.
4. Visual control
Visual signals are used to quickly and clearly communicate information.
Kanban is a “pull system.” Resources are controlled by replacing what has been consumed, as opposed to a “push system” where...