It is shocking but true: almost all manufacturing shop floors are inflicted by the 3Mu virus. This infection can, in fact, extend beyond the shop floor and afflict the entire organisation or supply chain.Though it is a common virus, it is not easy to identify or kill—and it is extremely challenging to keep it out forever. The three Mus—Muda, Mura and Muri—are three Japanese words that roughly translate into ‘waste’, ‘variation’ and ‘strain.’ Just as human health is dependent on the body’s ability to fight pathogens, shop-floor ‘health’ can be determined by the presence or absence of the 3Mu ‘virus’. This article explores this ‘virus’ from three dimensions: What is it? What are its symptoms? How can it be prevented or cured? About Muda Muda is a Japanese word that means ‘waste’. Here we refer to waste that occurs during activities within processes and not really waste in its physical form. That heap of defective or scrap material sitting on the shop floor is not referred to as Muda. Instead, Muda is the wasteful activities involved in inspecting the goods to find the defects or the rework that follows defect detection. In this case, inspection and rework will be Muda. These activities are performed by workers; they cost money and consume resources, but add no value. Activity that costs money, but adds no value to the customer, either internal or external, is Muda—the first and worst kind of shop-floor viruses.
 Muda is classically seen in eight forms: Unnecessary material transportation Unnecessary movements of people Rework or inspection to detect defects Delays due to people, material or machines Unnecessary processing—overkill Unnecessary production—producing more or faster than required Unnecessary inventory in any form-raw materials, work in progress or finished goods Finally, the killer—unused human skills and potential There is no hope for a cure unless one first has the expertise and skills to identify the Muda virus. In fact, identifying Muda by itself is half the cure. Though cures are available over the counter, self-prescription can be dangerous. The cure, in fact, starts with mental acceptance, followed by clear identification and measurement of the intensity of infection and, finally, following the prescription. All the eight Muda given above can be measured; and if they can be measured they can be improved. Muda: Symptoms and Prescriptions Unnecessary material transportation—layout redesign, FLOW/cellular production Unnecessary motion of people—apply principles of workstation design and motion economy Rework/inspection due to defects—eliminate causes of defects at the root Delays due to people, material or machines—use TPM, SMED, FLOW, internal Logistics Unnecessary processing—define customer needs and adhere to them Unnecessary production—line balancing, follow pull production and levelling Unnecessary inventory—kanban and pull planning Unused skills/ potential—total employee engagement (TEE), training within industry (TWI) and daily work management (DWM) About Mura Mura means ‘variation’—a deviation from a set standard or expected outcome. Mura is a rampant virus, inflicting all processes and work activities.Variation results in waste in the form of scrap, reworking or reprocessing. In a coffee shop, for example, two cups of coffee may not taste the same or have the same temperature, though they come from the same vending machine at the same point of time. One cup may require reheating—a clear waste of time and energy (not to mention the fact that reheated coffee may be rejected by the customer).
In the business world, there is frequently variation in business processes, products, materials, skills and output.Despite advancements in machines and in process technology, variation does occur and it is the management’s duty to identify, measure and eliminate all variation from the processes. Standard deviation is a statistical measure of variation or variability. It is denoted by Greek letter sigma. In industry processes, the state which is almost variation-free is known as Six Sigma. It is important to note that Mura results in Muda—that is, variation results in waste in the form of rework. When the expected outcome does not occur, it can safely be said that there is some Mura in the process. This can be in the form of variations in the quantity of output, quality of the output or delays in the process. For example, when there is a variation in a business process such as processing of payments, the number of payments expected to be processed in given unit of time might vary greatly or the payments processed may have errors and omissions. In the case of bottling liquids such as milk or shampoo, if each bottle coming off the line has more or less than the required volume, it means that there is variation in the filling line,which can be costly for the company. Most organisations prefer to build numerous checks, counterchecks and inspections into the process to catch variation. This, however, is hardly a solution, as it is done after the damage is already done.
The only sensible and permanent cure for variation is building a robust process. Companies must go upstream and fix the causes for variation. The best way to set off in this direction is to use a simple tool—the 5 Whys Analysis. There are many other tools to identify, measure and reduce process variation--the famous 6 QC tools, DOE, Shainin tools, among others. About Muri Muri means avoidable physical strain or burden on people and equipment. Some strain is to be expected at work, but when strain becomes excessive, it results in accidents or injuries. This, in turn, leads to poor output or quality errors in the products. A person working in extreme conditions caused due to excessive noise, temperature or fumes experiences Muri. With regard to equipment, Muri occurs when a machine operates over its safe limits or set performance limits. Overloading, abuse and poor maintenance of machines can cause Muri. This can result in equipment breaking down or performing under the expected output and quality limits.
Strain on equipment is easy to identify. Machines will shudder, squeak, leak, stop, produce defects and finally stop. When it comes to people, the signs may not be as obvious. Excess strain on an operator can be measured through on-site observations and trails. Management must learn to recognise the signs of strain and fix these problems before they escalate. If not, Muri will quickly result in Mura. Muri needs to be identified, measured and eliminated. Ergonomically-designed workstations, a good work environment and standardised work helps tackle Muri. Total productive maintenance (TPM) is a tested and proven system which eliminates strain on machines and equipment. Interestingly, a reduction in Muri results in; Heightened employee morale (due to close attention to ergonomics and safety) Higher quality Improved productivity, and Reduced costs. There is an urgent need to cut Muda across all shop floors, in fact, across all organisations—public or private, small, medium or very large. These viruses devour precious resources on every shop floor—every minute, every shift, every day, everywhere. We need to arrest this situation—shop floor by shop floor, organisation by organisation—before it becomes a national epidemic that cripples India’s competitiveness. The author is the Founding Partner & Director, Kaizen Institute (India, Africa & Middle East) and a Fulbright Fellow. He can be reached at jmurthy@kaizen.com |
