Waste refers to anything other than the minimum amount of equipment, materials, space, time, energy, systems and labor which are absolutely necessary to add value to the product.

In manufacturing, adding value is the increase of value of a product caused by the conversion process.

This raises a question; what about all the things we do in manufacturing which do not add value to the product? All activities add cost, because someone has to do them, but if they do not add value to the product we need to get rid of them, as they are a waste.

There are many things we do in our traditional factory that we take for granted as essential to the production process.

What about quality control? If you really think about it, quality control does nothing for the good parts, it only identifies the bad ones. We need therefore to learn how to stop producing bad ones and then we can get rid of quality control. Think about that well advertised slogan, "Striving for Zero Defect"; some companies are serious about it and use techniques such as process control to identify problems before they cause scrap.

They have put the responsibility of quality in the hands of the operators. This is based on the understanding that you cannot inspect quality into a product, only identify the bad ones. That is a little late when you have just made 1000 of them.

Those companies now regarded as "World Class Manufacturers" have put quality in the hands of their operators, supplying check jigs and using statistical control charts so they can see when the product being produced is getting close to the tolerance limit. The operator can then adjust the machine to bring the next one produced well inside the limit. This process prevents scrap being produced.

What about moving parts from one work center to another? This does nothing for the product except put it at risk of being damaged. The solution is to put the machines next to each other so we don’t have to move the parts from one end of the factory to the other. In other words we need to create work cells to remove the cause of the problem.

These are just two issues I have covered but also think about what putting items in stock, filing copies of documents, and items queuing in front of a work center do for our products. They all add cost but do not add value.

Part of the JIT process is to continually find ways of reducing waste and making the conversion process more effective. It has been found that the concept of continuous improvement with full worker involvement is key to this.

JIT has a lead time reduction focus which decreases the time and effort taken for activity, without a loss of quality. Waste in this sense goes beyond the traditional categories of rework and scrap to include excessive transport, handling, inventory and items such as insurance and security.

Just think how much time and money we waste in activities such as moving and storing work in process. Even the act of walking from one work center to another to deliver a manufacturing order is a good indicator of waste, of a non-value adding activity which we need to eliminate.

Every company has practices which are based on wasteful/unnecessary activities. We need to challenge everything we do to find out how we can become more competitive.
 

March 2000