When we think about lean manufacturing we think about work cells, kanban cards, TQM and so on. But many people do a basic mistake. That is the mistake of not understanding the concepts on which lean manufacturing built on. Many people who copied lean manufacturing failed because they did not understood the concepts behind lean manufacturing.

We shall give a simple definition to lean manufacturing before we go further. Lean manufacturing can be defined as a systematic approach to continuously identify and remove the wastes from the system. All the tools and techniques are based on fulfillment of this simple requirement.

To identify the conceptual difference between lean manufacturing and conventional manufacturing, we will have a look at the definition given above. There is a very important word to note. That is 'Removing'. Removing of waste from the system might not sound very different to minimization of wastes in the system, what we talk in conventional manufacturing. But think carefully. These two words are very different in the context of manufacturing (or even services).

When you think about minimizing of waste, you are thinking about the current system where you have wastes. You think about minimizing those wastes by fine tuning the system. When you think about eliminating or removing wastes from the system, you will have to find the causes for the wastes and remove them from the system. This means that you will have to redefine the process in a way that there are no wastes generated. So in the first case you live in the system where there are wastes, and struggle to get some improvement. In the later, you change the system so that system itself will not have the wastes. Aren't they really different?

I will give you one more example to clarify the conceptual difference between lean manufacturing and traditional manufacturing. Think about Work In Progress (WIP). In a traditional manufacturing process WIP is treated as an asset which helps to run the process smoothly. Lean manufacturing though, treats WIP as a waste itself. Further, lean manufacturing treats WIP as a mirror which reflects the imperfection of the system.

I can go on and on explaining conceptual differences these systems have. But it is very important to understand one thing about lean manufacturing. Lean manufacturing is not a fine tuning to the traditional manufacturing system you had. It is a completely different system. To be able to implement lean manufacturing correctly, understand the conceptual differences between lean manufacturing and traditional manufacturing.