Lean Manufacturing: The Toyota Production System

 Lean Manufacturing

a. Introduction

b. 14 principles of Lean manufacturing

c. types of waste according to Lean manufacturing

a. Introduction

    Lean is more a culture than a method, and there is no standard lean production model

“a way to do more and more with less and less - less human effort, less equipment, less time, and less space - while coming closer and closer to providing customers exactly what they want" and then translate this into five key principles:

1.    Value - Specify the value desired by the customer. "Form a team for each product to stick with that product during its entire production cycle", "Enter into a dialogue with the customer". Voice of Customer is one of the ways to achieve it.

2.    The Value Stream - Identify the value stream for each product providing that value and challenge all of the wasted steps (generally nine out of ten) currently necessary to provide it

3.    Flow - Make the product flow continuously through the remaining value-added steps

4.    Pull - Introduce pull between all steps where continuous flow is possible

5.    Perfection - Manage toward perfection so that the number of steps and the amount of time and information needed to serve the customer continually falls

The old way of doing things sees managers as people who should provide all the answers to workers on the ground. In lean thinking, however, everybody works together with a clear focus on customer value and continuous improvement. backed by a firm philosophical foundation of continuous improvement and learning. Behind the lean paradigm are a set of management principles that when consistently applied, result in business success regardless of one’s industry.

b. 14 Lean Management principles:

1.   Long Term Thinking

“Make decisions based on your long-term vision even if means making sacrifices in the short-term.

• Hoshin Kanri is a strategic planning tool that ensures the whole organization is aligned to a common goal and leaves little room for diversion. Everybody knows where the company’s direction and their responsibilities in achieving these goals.
• Nemawashi is a consensus-based decision-making approach that reduces the time taken to achieve results. By the time a formal meeting is held to make a decision, all involved parties have been consulted and have made up their minds on where they stand on an issue

2.   Flow the Customer Value

This principle deals with identifying wasteful activities that do not add any value to the customer. After determining the wasteful activities, efforts are made to either eliminate or reduce them

• Jidoka means building in quality into machines or process to prevent mistakes that have an impact on quality. This tool aims at capturing and correcting errors before they affect the next operation.
• Line balancing
• Cellular manufacturing

3.   Produce at the rate of customer demand

• Kanban System
• Takt Time- Takt time is a manufacturing term to describe the required product assembly duration that is needed to match the demand. It is the average time interval between the start of production of one unit and the start of production of the next unit, when items are produced sequentially

 

4.   Level the workload

• Heijunka is a Lean method for reducing the unevenness in a production process and minimizing the chance of overburden. The term Heijunka comes from Japanese and literally means leveling. It can help you react to demand changes and utilize your capacity in the best possible way. By implementing Heijunka, you can stop producing work in batches and start processing orders according to customer demand. Heijunka allows you to produce and deliver value to your customer at a steady pace so that you can react to fluctuations according to your average demand. For that purpose the method has two ways of leveling production:

1.     Leveling by volume

2.     Leveling by type

5.   Quality right the first time

• Jidoka- Also known as autonomation, it is a simple way of protecting your company from delivering products of low quality or defects to your customers while trying to keep up your takt time.

Jidoka relies on 4 simple principles to ensure that a company would deliver defect-free products:

1.     Discover an abnormality

2.     Stop the process

3.     Fix the immediate problem

4.     Investigate and solve the root cause

Jidoka is Automation with human touch

• Andon- which is also a signal to the process that an error has occurred that needs correcting.

6.   Standardize and Improve

Kaizen is a Japanese term meaning "change for the better" or "continuous improvement." It is a Japanese business philosophy regarding the processes that continuously improve operations and involve all employees. Kaizen sees improvement in productivity as a gradual and methodical process.

7.   Use visual controls

The purpose of visuals in a lean thinking organization is to communicate in a clear and unambiguous manner to the people working in a process as to the state of that process. 

• 5S is a systematic program that helps in orderliness and removal of waste
• Process control boards show the status of processes and whether or not they are within specified limits
• A3 reports capture all the necessary information needed in a summarized and concise manner to help in clear decision making
  

8.   Use the right technology

Lean thinking organizations do not install technology just because it is the in-thing at the moment. They seriously consider whether the technology will assist them to achieve the goals or whether it will be an impediment to the attainment of value for the customer

9.   Leaders are grown, not bought

This lean management thinking philosophy calls for the development of competent leaders from within an organization rather than always hiring from outside

This constant mentoring of leaders who thoroughly understand the work and live the philosophy of a company is critical in sustaining lean improvements because of maintaining institutional memory.

10.  personal development of people

Lean continually challenges team members to do their best to solve common business problems. By empowering the workforce to take charge of solving their problems, lean companies improve their skills which ultimately has a significant impact on the business.

The Job Instruction Method perfected at Toyota is one of the essential tools for improving the skills of the workforce in a lean environment

11.  Treat partners with respect

Lean thinking organizations work with their suppliers and help them to improve for the benefit of all the stakeholders. They understand that their success is dependent on the success of all in a win-win relationship that is defined by mutual respect and cooperation.

12.  Gain a first-hand understanding of problems

Genchi genbutsu means “go and see” the source of a problem and find out what the exact causes are. It is a lean way of thinking that is not satisfied with second-hand reports but calls for real confirmation at the ground.

13.  Build consensus before acting

The nemawashi consensus-building approach is the fastest way to gain acceptance of lean initiatives through prior consultations before making final decisions.

14.  Become a learning organization

This principle of lean management emphasizes the need for continuous evolution through constant reflection and re-adjustment based on the learning gained in the lean journey. Businesses must not stagnate in the past, but should continuously evolve to meet current and future challenges.

Types of Waste in Lean Manufacturing

Waste is not a simple concept. If approached simply, then the reduction is going to be limited. In order for lean project management to be most effective, waste is defined in three specific ways.

·         Mura: Unevenness, or waste due to fluctuations in demand. This can come from customer requests, but it can also be due to an organization adding new services and thus additional work.

·         Muri: Overburden, or waste due to trying to do too much at once. This has to do with resource allocation. When too few people try to do too much work, they often waste time switching from one task to another.

·         Muda: Non-value-adding work, or process waste. This waste comes as a byproduct of something else. Think about three things: value, work that adds immediate value for a customer; necessary waste, which are supporting activities that add value; and unnecessary waste, activities that don’t add value. Therefore, lean maximizes value, minimizes necessary waste and removes unnecessary waste altogether.