Lean manufacturing: A closed loop system?

If you have studied the subject of control systems, you should have studied two types of systems. They are open loop systems and closed loop systems. Main difference between these two types of systems is the feedback loop. Closed loop system has a sensing mechanism which will sense the output and compare it with the desired result. If there is a variation the system will act accordingly. Open loop systems are faster and cheaper to create and operate. On the other hand closed loop systems provide the feedback of the out put and adjust the system accordingly. But they are little slower and costly to create and operate. Below is a graphical representation of open loop and closed loop systems.


If we closely study any manufacturing system, it has many smaller systems which make the bigger system. Requirement of controlling comes up when the system has a higher tolerance level and unpredictability. So the actual output can vary considerably from the desired result. So at every stage there should be a controlling mechanism which will provide some control over the result. If the actual result is considerably different to the desired result the system will stop or give some sort of a warning. Higher the risk of this happening, there is a requirement for the feedback and hence for the closed loop systems. Of cause it is very important to stop and fix any problems when they occur. This is a very important aspect of lean manufacturing as well.

But for me the lean manufacturing is a closed loop system at very lower levels of operation. The operation is closed loop at operator level. Every operator checks their product and if there is a variation with the desired result, they will stop the system and try to fix the cause of the problem. But in the bigger picture it is more of an open loop system of manufacturing. It has a defined input. And it has a well defined output. In between manufacturing system looks at meeting these outputs with the inputs. Systems are fine-tuned so that they will give the desired results most the times. For an example raw materials are source inspected and only the quality raw material is available for manufacturing. So there is a minimal chance of problems in processing. If there is a problem with desired output system will be stopped immediately and the problem will be corrected.

Lean manufacturing, although it has a feedback path and stops when there is a problem, it always looks to operate as an open loop system. This is facilitated with standard ways of working, aligning suppliers and even customers in getting the desired result, and source reduction of problem.

If you have a different view on this please leave a comment.

What would it feel to work in Toyota

Every lean manufacturer would like to work for Toyota at least to experience in first hand how they work. The Toyota production system caught the attention of manufacturers all around the world in past two decades. Most of the manufacturers are trying to implement lean methods in their organizations to improve performance. Their model is Toyota.

What would you think when thinking about lean manufacturing environment? One comes with a great new idea. Managers and workers get together to discuss the idea. Then the decision is taken to implement and then the decision is implemented. This would be the perception most of the people have on Toyota and lean manufacturing. But the reality might be something different.

In Toyota, resistance to change, conservative approach to work is present. This was nicely explained in the book “The Toyota Way” by Jeffery K Liker when he describes the development of Lexus the luxury brand of Toyota. From the beginning where the requirement was identified, to the identification of the specifications and to the designing and manufacturing the engine and till to the end Liker describes the challenges faced by people at all levels.

When you read this book I am sure your perceptions on Toyota will be challenged. You will understand Toyota is not much different to the traditional organization by many aspects. You might start to think that your way of operation is even better. But Toyota has very important difference to the traditional organization. They have a culture where every problem is analyzed and decisions are made by living the values of this culture. This culture is built on lean thinking and lead by leaders who clearly understand the values of the system.

Unlike many traditional organizations, when Toyota hits a roadblock, they have a clear system and method of thinking to guide them. In “Toyota way” Liker has explained how these concepts and principles have used in solving problems. This makes the difference. Thankful to the efforts of all the engineers and marketers involved, Lexus is the best selling luxury vehicle brand in US.

Lean manufacturing and simplification of process

Most of the organizations in today’s highly competitive business environment is been forced to do better in terms of price, quality, delivery, environment and society. This has made manufacturers and service providers to explore the possibilities of improvement. So managers and executives are very busy nowadays of identifying problems and improving their organizations. In the process most of the organizations have introduced many controls, processes and ERP and so on. This actually will help most of the organizations to achieve the efficiencies they are looking for in short term. But in long term so many controls, processes and managing principles makes it very difficult to maintain and will fall apart eventually.

On the other hand lean manufacturing uses a unique approach to this. They look at the root causes and treat those root causes. Simplifying the processes is one key success factor of lean. Their problem solving methodology is simple. Go and See it for you is one of lean manufacturing’s very important methods of solving problems. This will reduce the need for many complex computer programs and hardware. This will make the decision makers more involved in the process. Finding of root causes is done with the technique called “ask why five times”. Simply people will go to the place where the problem has occurred and will find out the root cause for that problem. Simple isn’t it? No need for computers, long hours of work. People can identify the place where that problem occurred by simply looking at the factory premises. This is known as visual controlling.

When we think about any complex process it is not the process which is complex, but the methods we use in that process makes it complex. Simplify the process. This will make the life easier for everybody in the organization, from the shop floor worker to the CEO. This is one major differentiator of lean manufacturing and lean management to the traditional manufacturing and management.

Lean manufacturing and technology

In most of the organizations workers in all levels from CEO to the shop floor are very much eager to use new or the “cutting edge technology” in their day to day operations to make their lives easier. Every organization use new technology in the form of computers, software and automated tools and newest techniques.

It is very important to use new technology. That can really boost the performance of your organization with these tools. But lean manufacturers take a different approach to this. One of the prime lean manufacturing concepts is the usage of stable thoroughly tested technology, if it is required. This is an approach all the organization must look at when they are seeking for new technology.

People use technology to make their work easier. But even in your organization, how many times have you found new technology as a trouble maker. First of all you must identify your requirements correct. Most of the organizations seek answer for the problems without knowing what their problems are. For them the standard answer for their problem is technology.

Understanding the requirement correct will give lean thinkers the ability to evaluate the requirement of technology. If the technology can solve your problem, you must first have better manual processes. Without humans being able to do something effectively, machines will never be able to. Choosing of the technology must be done very carefully. All the possible scenarios must be tested and evaluated. Also the cost factor, durability and fit for the purpose are must considerations. Over sophistication will make the maintenance hard and will make the systems less flexible.

Cutting edge technology might be necessary for you. But in most of the cases technology will not be able to solve your problems. You have to dig deep in to the process and find out the root causes for your problems. If technology can play a role, use tested and stable technology. Cutting edge technology is also known as “bleeding” edge technology. Lean manufacturing is always about concepts, not about tools.