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.

 

Lean Production

Flickr © Nicole Yeary

Flickr © Nicole Yeary

The idea of lean production was first analyzed in depth by John Krafcik when he and others were working on a motor vehicle program in the late 1980s. The idea was later popularized in The Machine that Changed the World (1990) by Womack, Jones and Roos.

Lean Production is ‘Lean’ because “it uses less of everything compared with mass production: half the human effort in the factory, half the factory space, half the investment in tools, half the engineering hours to develop a new product in half the time. Also, it requires far less than half of the needed inventory on site. The expected results are fewer defects, while producing a greater and ever growing variety of products.”

Lean thinking can be applied to manufacturing firms as well as service organizations and can be applied across all areas of business. It is a three-pronged approach that incorporates a belief in quality, waste elimination and employee involvement supported by a structured management system. James P Womack introduced five key principles that underpin the lean philosophy:

Specify what creates value as seen from the customer’s perspectiveThis implies a need for close relations with the customer to ensure that his perception of value is embodied in what the supplier is offering. It is not safe to assume that the customer has the same perception of value as the supplier.

Identify all steps across the value The key term is value stream. In a traditional supply chain, there will be many activities and processes that do not add value. In a lean chain, the aim is to eradicate these, leaving just a stream of value adding activities. The task of Asprova’s Synchronized Finite Capacity Scheduling feature is to determine this value chain on the basis of available capacity of resources, it eliminates all actions that are of no significance.

Perform those actions that create the value flow Once the value adding activities are identified, consider how to link them so as to deliver the total value to the end customer.

Only make what is pulled by the customer just in time This is a distinguishing feature of lean and agile philosophies. The traditional model of manufacturing often leads to production in advance of customer requirements (whether it refers to internal or external customers). Lean and agile production avoids this function.

Strive for perfection by continually removing successive layers of wasteThis refers to avoidance of waste. Lean production utilizes and further develops the concept of ‘seven wastes’ pioneered by Taiichi Ohno.

Asprova’s planning and scheduling features are conducive for establishing lean production in the manufacturing firms. It synchronizes sales and operation functions and shortens lead time which removes waste in the form of avoiding overproduction and reducing inventory levels.

 

 

 

 

Source: Womack, Jones and Roos, The Machine that Changed the World, Published in 1990
Photo credits: Flickr © Nicole Yeary