What is Lean Production?
- Lean production aims to eliminate waste and maximize the value of a product based on the perspective of the consumer.
- Lean production considers product and process design as an ongoing activity and not an one-off task, and should be viewed as a long-term strategy.
Example
Toyota was inspired by the model of Just in time supermarkets in the United States.
They figured that if they could get all materials used in the manufacture of their vehicles to arrive just in time for production, they could reduce waste and speed up production.
They also went about looking for other ways to reduce waste (time, energy or materials) in order to produce a truly efficient manufacturing system.
What they created came to be the model for ‘Lean Production’.
Characteristics of Lean Production
JIT Supplies
- Getting the right amount of material to the production line just in time.
- Not having to spend money on keeping extra stock in storage.
Highly-Trained and Multi-Skill Workforce
- Having experts in place to ensure that no time is wasted.
- Ensures higher efficiency.
Quality Control and Continuous Improvement
- Checks are made at every stage of production to quickly identify and fix any problems that arise.
- Improvements to the system are actively sought.
Zero Defects and Zero Inventory
- Ensure that time, material and energy is not wasted producing a substandard product.
- Reduce possible errors as much as possible, focus on standardization.
- Products are manufactured just in time to be sold, no extra inventory is kept.
Principles of Lean Production
- Eliminating waste
- Minimizing inventory
- Maximizing flow
- Pulling production from customer demand
- Meeting customer requirements
- Doing it right first time
- Empowering workers
- Designing for rapid changeover
- Partnering with suppliers
- Creating a culture of continuous improvement (Kaizen)
Advantages
- Increased productivity because of focus on continuous improvement and waste reduction.
- Increased quality of product thanks to focus on improvement and reduction of defects
- Cost reduction because manufacturer is able to pass on cost savings to the customer, as cheap production costs allow for a cheaper product while still making profit.
- Increased profits through cost reduction and increased customer satisfaction.
- Improved working conditions for employees.
- Competitive advantage because of focus on cost reduction and productivity.
- Reduced environmental impact due to reduction of waste of materials and resources.
Disadvantages
- High capital costs due to the need to invest in JIT systems and IT systems.
- Difficult to introduce to existing workforce as some workers and managers may resist the change in manufacturing approach.
- Dependent on a highly integrated system, as if there is a breakdown in communication, deliveries, or production, the whole manufacturing system can come to a halt.
- No inventory can make it difficult to respond to sudden increases in demand or create a buffer in case of a production slowdown.
Tools for Lean Production
Value Steam Mapping
- A lean production management tool used to analyze current and future processes for the production of a product through to delivery to the consumer.
- Value stream mapping allows production managers to plan the manufacture of a product from start (purchase of raw materials) to finish (sale to customer) and identify potential problems in the system.
- This ‘big picture’ view provides production managers with the necessary overview to plan where they can make improvements to the process in order to speed it up.
Workflow Analysis
- Workflow analysis is the review of processes in a workflow, for example, a production line, in order to identify potential improvements.
- Where value stream mapping provides a ‘big picture’ of the manufacturing process, workflow analysis is concerned with the details of the production line.
- Workflow analysis considers the sequence, tools and even worker movement to ensure the highest possible efficiency in the system.
Product Family
- A group of products that have common classification criteria.
- Members of a product family normally have many common parts, assemblies, production processes and processing methods, are branded consistently and share aesthetic characteristics.
- The essential idea behind product families is to create a production line with a synchronized and efficient flow that allows products to be produced at a predictable, market-driven rate.
- Common parts and assemblies allows for more unified and efficient assembly lines.
- Companies and designers will develop a successful product or product range into product families.
- This further develops a successful market segment that is already familiar with the original product.
- For example, iPod then iPhone, then iPad etc.
Role of the Workforce
Training
- The development of a highly skilled workforce can build deep understanding of how the production process works and allow workers at all levels to identify areas of the workflow to be improved.
- This leads to the devolution of power.
Devolution in Power
- Understanding that the best people to identify improvements of a product or system are those who use it, companies striving for a lean production system ensure that all members of the workforce are able to contribute to the design of the system.
- This benefits the company, which is able to streamline processes and reduce costs and also empowers the workforce and gives them a sense of ownership and loyalty to the company.
Kaizen 改善
- Kaizen is a culture of continuous improvement originating in Japan and considered an important aspect of an organization's long term strategy.
- This has been central to the success of many Japanese companies such as Toyota.
- It empowers the employees by including them in decision making and to provide continuous training.