Lean Operations

McGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.

You should be able to:1. Explain what is meant by the term lean operations system2. List each of the goals of a lean system and explain its

importance3. List and briefly describe the building blocks of lean4. List the benefits of a lean system5. Outline the considerations important in converting a

traditional mode of operations to a lean system6. Point out some of the obstacles that might be encountered

when converting to a lean system7. Describe value stream mapping

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Lean operation

A flexible system of operation that uses considerably less resources than a traditional system Tend to achieve

Greater productivity

Lower costs

Shorter cycle times

Higher quality

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The ultimate goal:

Achieve a system that matches supply to customer demand; supply is synchronized to meet customer demand in a smooth uninterrupted flow

A balanced system One that achieves a smooth, rapid flow of materials and/or

work through the system

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The degree to which lean’s ultimate goal is achieved depends upon how well its supporting goals are achieved:1. Eliminate disruptions

2. Make the system flexible

3. Eliminate waste, especially excess inventory

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Five personnel/organizational elements that are important for lean systems: Workers as assets

Cross-trained workers

Continuous improvement

Cost accounting

Leadership/project management

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Seven elements of manufacturing planning and control (MPC) are particularly important for lean system:1. Level loading

2. Pull systems

3. Visual systems

4. Limited work-in-process (WIP)

5. Close vendor relationships

6. Reduced transaction processing

7. Preventive maintenance and housekeeping

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Preventive maintenance

Maintaining equipment in good operating condition and replacing parts that have a tendency to fail before they actually do fail

Housekeeping Maintaining a workplace that is clean and free of

unnecessary materials

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1. Make sure top management is committed and that they know what will be required

2. Decide which parts will need the most effort to convert

3. Obtain support and cooperation of workers

4. Begin by trying to reduce setup times while maintaining the current system

5. Gradually convert operations, begin at the end and work backwards

6. Convert suppliers to JIT

7. Prepare for obstacles

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1. Management may not be fully committed or willing to devote the necessary resources to conversion

2. Workers/management may not be cooperative

3. It can be difficult to change the organizational culture to one consistent with the lean philosophy

4. Suppliers may resist

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In service the focus is often on the time needed to perform the service because speed is often the order winner

Lean benefits can be achieved in the following ways: Eliminate disruptions

Make system flexible

Reduce setup and lead times

Eliminate waste

Minimize WIP

Simplify the process

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JIT II:

A supplier representative works right in the company’s plant, making sure there is an appropriate supply on hand

It is often referred to as vendor managed inventory (VMI)

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Be careful to study the requirements and benefits of lean systems before making a decision to convert operations Evaluate strengths and weaknesses of current operations

The decision to convert can be sequential

Weigh the pros and cons of a lean approach to inventories

Supplier management is critical to a lean operation

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