Muda, Muri and Mura

farhanWhen you ask a number of people to explain Lean Manufacturing in one sentence, most of them will answer: “eliminate waste”. The reason is that eliminating waste or Muda is a relatively easy way of indentifying the low hanging fruits for improvement in an organization. However, Muda is not the only ‘M’ Toyota has built its famous Toyota Production System around, there are two more: Muri (Overburden) and Mura (Variation).

Muda (無駄) is a general Japanese term for an activity that is wasteful or is unproductive, etymologically or un-useful (駄) in practice or others. A process consumes resources and adds value by producing goods or providing a service that a customer is willing to pay for. However, waste occurs when more resources are consumed than are necessary to produce the goods or provide the service that the customer actually wants. The main causes of these time and resource wasting activities are mostly: lack of communication, inefficient resources or not understanding the requirements of the customer specs. This means, if a process is to be effective, then every activity must be properly documented; communication must be adequate; and customers’ need must be understood as much as possible.

Muri (無理, “unreasonable”) is a Japanese term for overburden, unreasonableness or absurdity. It is based on the belief that “excessive strains put on the development processes and teams are most likely to result in unrealistic outcomes with limited time”. When a situation such as this arises, it is most likely due to inadequate skills, poor planning, under estimation and poor task schedules. So, how can these types of events are avoided during production? The answer is simple: plan the manufacturing process well; prioritize activities, understand the process variables such as time, resources, and skill levels of workers; ensure estimation is done correctly, etc. Identifying the balance between not enough work and too much work is a delicate and difficult point to achieve, but becomes one of the hallmarks of the Toyota Way.

Mura (斑 or ムラ)[ is a traditional Japanese term for unevenness, inconsistency in physical matter or human spiritual condition. Unevenness can be found in fluctuation of customer demand, process times per product or variation of cycle times for different operators. Mura is avoided through Just In Time system which is based on little or no inventory, by supplying the production process with the right part, at the right time, in the right amount, and first-in, first out component flow. Just in Time create a “pull system” in which each sub-process withdraws its needs from the preceding sub-processes, and ultimately from an outside supplier. When a preceding process does not receive a request or withdrawal it does not make more parts. This type of system is designed to maximize efficiency by minimizing storage overhead.

Asprova has been instrumental in improving productivity by ensuring existence of only value adding activities in the supply chain. Our advanced planning and scheduling features assist manufacturing companies to identify the best way of doing the job through the removal of unnecessary financing costs, worthless inventory and overworked employees, thereby establishing a smooth flow of standardized work.


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