lesson 307 step 5 reduce changeover times part 2 rev...

10 Steps to become a

Lean Enterprise

Lean Expert Training Course

Step 5

Reduce Changeover Times

Part 2

Lean Expert Course Workbook - Step 5 Reduce Changeover Times Part 2

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Copyright Radical Transformation LLC www.radical-transformation.com Rev 1

Table of Contents

Welcome................................................................................................................................................ 3

Course Objectives ................................................................................................................................ 4

Four Steps to Reduce Changeovers ................................................................................................... 5

Observed Changeover ..................................................................................................................... 6

Step 1 - Document and Record Activities ........................................................................................... 7

Travel Diagram .................................................................................................................................. 8

Changeover Elements Analysis ....................................................................................................... 9

Step 1 Summary ................................................................................................................................. 10

Step 2 - Define Internal and External. ............................................................................................... 11

Separate into Internal and External Activities............................................................................... 12

Internal and External Analysis ....................................................................................................... 13

Step 2 Summary ................................................................................................................................. 14

Reference Materials ........................................................................................................................... 16

Documents List ................................................................................................................................... 17

Please note that some of the screens in the online course have been omitted from this workbook. This is to protect any proprietary i nformation that may be included in the pictures.


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Welcome. We would like to welcome you back to our next module in this online training course. This training module is called “Step 5 – Reduce Changeover Times Part 2.” This module is a continuation of our Lean Expert online course series called “10 steps to become a Lean Enterprise.” This program has been specifically designed to demonstrate our step by step methodology that will allow any organization to become a Lean Enterprise. Let’s continue your lean journey!


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Course Objectives Here are the course objectives for Step 5 – Reduce Changeover Times Part 2. We specially designed this course to give the information you need to get a full understanding of each step required to become a Lean Enterprise. Upon completion of this course, you should be able to:

• Understand the 4 steps to improve changeover times.

• Understand Step 1 – Document and record changeover activities.

• Understand Step 2 – Separate changeover activities into internal and external

elements.

Now we are going to work through each course objective.


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Four Steps to Reduce Changeovers These are the four steps to reducing changeover times. In the following training modules of Step 5 – Reducing Changeover times, we will discuss these four steps in detail. The four steps are:

1. Document and record a changeover to identify the activities. 2. Separate activities into internal and external elements. 3. Convert internal elements into external elements. 4. Streamline all aspects of the changeover process.

Each of these steps is a critical element of reducing changeovers. Each step must be performed in the prescribed order.


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Observed Changeover As we mentioned in a previous screen, most people see changeover time as one complete activity. To them, it starts when the machine stops and is completed when the machine starts up again. We have demonstrated this in the “Before” diagram in this screen. In reality, there are many things happening during the changeover time. To identify each of these activities we will use a process called “SMED”. This is an acronym for “Single Minute Exchange of Dies”. It is a process developed by Shigeo Shingo to reduce equipment changeover times. SMED involves a process of observing changeovers to identify all the specific activities. We will go through each of the SMED steps during the Step 5 – Reduce Changeover Times training series.


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Step 1 - Document and Record Activities Start by capturing all of the changeover activities. One of the methods to do this is to use video. This will allow an improvement team to review the video as often as they need to see it. Later, the video can be adapted for training purposes. While the changeover is being observed and recorded, conduct a time study of the entire process. Try to break the work down into easily manageable chunks or elements of activity. Changeover data can be gathered from several sources. Here is a list of some typical data archives:

• Research historical data of changeover times.

• Average run cycle times and batch sizes from a production department database.

• Number of changeovers per week/month/year.

• Equipment layout and process flow from previous improvement events.

• Current changeover procedures.

• Personnel (types of skills required) from the Human Resources or Training department.

Archive the data in a place that is easily accessible to everyone that would need it in the future. It can be stored on paper or an electronic format. Use the principles of workplace organization to manage the data.


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Travel Diagram The purpose of a travel diagram (or spaghetti diagram) is to determine the amount of travel that occurs during a workday or shift. The travel diagram is a tool used to observe and record the actual travel to and from locations inside and outside of the work area. It is used to document the direction and distances traveled by materials, information, equipment, and people. In any business, time equals money. The time taken for an employee to walk to and from a location to retrieve something will have a cost attached to it. One way to reduce cost is to eliminate the travel time. The more something or someone has to move around the workplace, the longer it takes to produce the end item. This will increase the cycle time and the cost of the finished product or service. In the following screen is an example of a travel diagram from an actual event.


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Changeover Elements Analysis In this screen, there is a sample data collection sheet. It is used to observe and record all the activities that occur during a complete changeover. You can see that the clock times and changeover activities have been entered onto the sheet. The person conducting this data collection process would have started their stopwatch and allowed it to run continuously throughout the changeover. As each activity starts and ends they would write down the time and record the details of the activity as it was happening. It is important to record the changeover event as a series of elements. For example, try to capture and isolate the time a worker walks to another area of the facility to get equipment or tooling. Each element of time should record a specific type of activity such as “get equipment” or “put away equipment”. The reason for doing this will become clear as we work through the rest of this training module.


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Step 1 Summary At the end of Step 1 the changeover activities have been observed, documented, and time studied. The total changeover process has been captured. As we mentioned in a previous screen, most people see changeover time as one complete activity. To them, it starts when the machine stops and is completed when the machine starts up again. We have shown this in the “Step 1” graphic in this screen. Now, we are ready to move onto Step 2 – Separate changeover activities into internal and external elements.


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Step 2 - Define Internal and External. In reality, there are several things happening during the changeover time. To identify each of these activities we will use a process called “SMED”. This is an acronym for “Single Minute Exchange of Dies”. It is a process developed by Shigeo Shingo to reduce equipment changeover times. SMED is a process of observing changeovers to identify all the specific activities. These are separated into two categories: internal and external.

Internal activities can only be completed when the machine has stopped. External activities can be completed at any time. However, it is preferable to perform them while the machine is still working and producing.

In the following screens we will go into detail about the process of separating internal and external activities.


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Separate into Internal and External Activities It is necessary to differentiate between internal and external activities. In the previous screen, we gave a definition of these two categories of activity.

Internal activities can only be completed when the machine has stopped. External activities can be completed at any time. However, it is preferable to perform them while the machine is still working and producing.

Here are some examples of internal and external activities:

• External: Get equipment. If the person has to walk away from the machine to get

something, it is an external activity.

• Internal: Making the final adjustments to a machine setup is done when the

machine has been stopped.

• Internal: When equipment such as a punch is being moved in and out of the

machine. This can only be performed when the machine has stopped.

• External: If a person has to search for parts, equipment, tooling, information, etc.

These can be done while the machine is still working and producing.


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Internal and External Analysis In the screen, you see the data collection sheet from Step 1. You will notice the two right hand columns with the headings of internal time and external Time. They have been populated with numbers to show the type of activity, i.e. internal or external, and the actual time taken to perform each activity. The time is calculated by using the observed time from the clock time column on the left side of the sheet. The machine was stopped at 08:00 and this was recorded in the clock time column. It took the machine operator a total of 5 minutes to bring the machine to a complete stand still which was recorded at 08:05. This activity was identified as an internal process because the machine was not safe to work on until it had stopped. The next process started at 08:05. From 08:05 the changeover team went to get their lifting gear and bring it back to the machine. This activity was completed at 08:30, which means it took the team 25 minutes to perform this task. This activity was identified as an external process because it could have been completed while the machine was still running. If the team had the lifting gear ready when the machine stopped, it would not have to wait to start the changeover. Remember, waiting is one of the eight wastes. Each activity is identified as internal or external and the time it took to perform it is calculated. At the bottom of the sheet, you can see the total time for the changeover, which was 270 minutes. The time breaks down into 175 minutes of external and 96 minutes of internal activities.


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Step 2 Summary At the end of Step 2 the changeover activities have been separated into internal and external elements. Notice the difference between Step 1 and Step 2. In Step 1 all the changeover was an internal activity, that is, it all occurred while the machine was stopped. In Step 2 we differentiated between what was a potential internal or external activity. We have shown this in the “Step 2” graphic in this screen. The time for the observed changeover was 270 minutes. This was separated into 175 minutes for external and 95 minutes for internal activities. What is this data telling us? It is clearly demonstrating that a total of 175 minutes of the activity could have been performed while the machine was still running. If this had happened, the machine would have only been down for a total of 95 minutes. The consequence for the company was it lost 175 minutes of production time because it did not know the difference between the internal and external elements of changeover time. Now we are ready to move onto Step 3 – Convert internal elements into external elements.


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End of Presentation Congratulations, you have now completed this presentation. Please go to the next training module in your Lean Expert online course materials.


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Reference Materials

1. Quick Changeovers for Operators: The SMEDSystem.

By: Productivity Press Development Team. Published by Productivity Press 1996. 2. Quick Changeover Simplified -The Manager's Guide to Improving Profits with

SMED. By Fletcher Birmingham and Jim Jelinek. Published by Productivity Press 2007.

3. Kaizen for Quick Changeover: Going Beyond SMED. By Keisuke Arai and Kenichi Sekine. Published by Productivity Press 2006.


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Documents List

1. Quick Changeover Analysis Sheet


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