What Is Lean Manufacturing?
Lean is a discipline focused on improving process speed and eliminating waste.
The pursuit of the elimination of waste has led to several quality improvements. The earliest development here is Poke Yoke (mistake proofing) developed by Shigeo Shingo in Japan in 1961. The essential idea of poka-yoke is to design processes in a way that mistakes are impossible to make or at least easily detected and corrected. Poka-yoke devices fall into two major categories: prevention and detection. A prevention device affects the process in such a way that it is impossible to make a mistake. A detection device signals the user when a mistake has been made, so that the user can quickly correct the problem. He later developed Single Minute Exchange of Die (SMED) in 1970. This trend has also seen more of a system wide process mapping and value analysis, which has evolved into Value Stream Maps.
Six Sigma Professionals, Inc. Lean practice utilizes "Kaizen events" -- intensive, week-long improvement sessions -- to quickly identify improvement opportunities and goes one step further than a tradition process map in its use of value stream mapping.
Value stream mapping originated to document manufacturing processes that are to be improved using lean manufacturing methods. They are most useful with higher frequency processes even if considering mixed models. However, it is equally applicable to service processes. Usually, whenever there is a product/service for a customer, there is a value stream. Therefore, value stream mapping is applicable whenever the design team is trying to make eliminate waste in a process - eliminate non-value added steps, actions and activities. A value-added activity or step is any activity or things the customer is willing to pay for. For example, no customer will pay for quality inspection it’s expected as part of the process. The non-value added activities are the activities that do not add market form or function or are not necessary. They should be eliminated, simplified, reduced or integrated.
Visibility to waste can be assured via a scorecard documenting performance of variables (metrics) such as non-value added cycle time, inventory, rework, and defects. Such measurements should be taken within a broader scope of a value stream management process. Value stream management is the process of increasing the ratio of value to non-value by identifying and eliminating sources of waste. Waste and non-value added activities exhibit themselves in several formats:
- Unnecessary movement of people
- Overproduction ahead of demand
- Unnecessary movement of materials
- Waiting for the next step (idle time)
- Over-processing
- Production of defective products (measured in services per million, defect per million, or defect per million opportunities)
- Extra Inventory
Lean manufacturing techniques remove waste and non-value-adding activities from processes to enable the production and delivery of products and services at customer demand and at lower cost. Value stream mapping is a major technique within the lean the toolbox.
Like other techniques, the value stream mapping technique provides a common language and understanding for talking about manufacturing & transactional processes. It is a guide to develop vision (future state map) and identify and prioritize initial opportunities and improvement actions.
On another hand, SSP Lean Six Sigma would leverage all the standards, documented process, and data already available in your organization. Lean Six Sigma would introduce tools that would help develop process maps with a level of measurable detail that allows identification of non-value-added steps (removal of which will make processes more efficient). It introduces another level of customer focus and a formal methodology (Six Sigma) to execute change across functions. It also would engage management and leverage dedicated resources against the projects with the biggest financial impacts to the strategy of the organization.