Simply speaking muda is the opposite of value, that is, anything that the customer is not willing to pay for. This is the biggest obstruction to productivity improvement or process excellence.
From a manufacturing perspective we can look at it as those elements of production that add time, effort, cost but no value. Generally there are 7 forms of MUDA.
muda of Overproduction
Overproduction is sometimes called the Mother of all MUDA’s. Taichi Ohno saw it as the root to all manufacturing evil.
Overproduction arises from fear or concern of stock outs or a misunderstanding of demand or cost. It is rarely, if ever from real necessity.
muda of Inventory
Overproduction invariably leads to the muda of Inventory.
Inventory needs space, costs money, requires finding, needs intermediate storage and people to move it, can be damaged, can delay urgent orders and can hide problems.
The sea of inventory
Inventory is often created as a safety stock for machine failures in large batch processes. In a sense, inventory is a buffer for hidden problems. Bringing down inventory levels exposes these problems. Hence inventory reduction is generally a very painful exercise as problems that were once submerged start surfacing. Here we must go back to our KAIZEN™ Principles – Welcome Problems, Make problems visible. We must allow Inventory reduction to bring out these problems and then try and solve them. Increasing inventory to submerge the issue is not the answer.
muda of Waiting
muda of waiting can arise from Man, Material or Machine not being able to proceed due to lack of either or both of the other two. Materials could get stuck if a machine is not functioning. Man could have no work if materials are not available.
Wasting is also a result due to unbalanced work, minor stoppages and time for start up of machines, quality inspection, watching machines in operation, product damage and tool changes.
muda of Transportation
muda of transportation refers to all transportation of Materials. Fundamentally, it is important to recognize transportation adds no “value” and hence is a Muda. It is different matter that we may need some transportation (to get the goods to the market for example). Transportation leads to cost, possible damage of goods, searching for goods to be transported, time lost in the transportation, possible spillage and wasted time in logistics equipment.
In case you missed it, my last post was IndiZen 2017, 8th National Convention on Operational Excellence.
And, if you wish to read & learn more from our blog, click here to follow our blog by subscribing the same.