Single Minute Exchange of Dies (SMED) is a methodology to reduce the change over time. Reducing the changeover time is a key enabler of reducing the batch sizes and hence the lead time.
To add this tool your workbook, click on Lean and then select SMED Analysis.
Click on Analysis Setup to open the menu options for this tool.
A sample screenshot of the setup menu is shown below.
Num Rows: Specify the number of rows to format the worksheet. You would at least need to have as many rows as the number of steps in your process. You can always go back and change this number later.
Reduction Target: The % reduction in changeover time that you expect by performing the SMED exercise. The actual value you achieved will be compared with this target in the final report.
SMED Video: Select a video of the changeover event and upload it to your Excel tool. This video is optional, but it can provide a mechanism for you to view the different activities that are conducted in the changeover and the time it takes for each step. The output of this analysis will be an input into your worksheet.
Click on the Browse button to search your hard disk to load a video file. If you click on Cancel, any previous selections are canceled. Note that once a video is upload to the worksheet, you will not be able to delete the video from this dialog box, but you will have to manually delete the videos from your worksheet "Comments" area. You can upload multiple videos to your worksheet - preferably one for the before condition and one for the after condition. Click on the Clear button to remove the file from the dialog box.
Click on this button to open the example file. You can view the example to get an idea of how to fill out this tool or you can use the example as a starting point and modify it to meet your project needs.
Help Button: Click on this button to open the help file on this topic.
Cancel Button: Click on this button to exit without saving any changes.
OK Button: Click on this button to save changes and update your analysis results.
Enter the following information on the worksheet:
List all the activities for changeover on the worksheet. Here are the columns you can specify:
A number for the sequence of changeover activities
A brief description of the activity being performed
The name of the operator(s) performing the activity
The start time for the activity in hh:mm:ss
The end time for the activity in hh:mm:ss
Whether the activity is internal or external. Internal activities are those that can be done only when the machine/equipment is stopped. External activities are those that can be done when the machine/equipment is running.
The state for the activity - whether it is current state (what is happening today) or future state (what you are proposing)
A classification of the activity as either VA (Value Added), NVA (Non Value Added), or BVA (Business Value Added)
The methodology to reduce the changeover time in the future state vs. the current state could include the following steps:
Convert as many internal activities to external activities if possible.
Eliminate or reduce non value added activities.
Combine different activities into one if possible.
Possibly break-up the activities and assign it to different people to perform the activities in parallel.
Try to minimize the time spent on internal activities.
Try to eliminate or minize the business value added activities.
Use tools such as jigs and fixtures to simplify the time spent on the activities.
Use pre-kit parts to minimize the time required to perform the activities
Deploy the suggested changes (after approval from management) and collect the time it takes to perform the new activities. You can use a video of the new process to document the times. Any future state now becomes the new current state and the same process can be repeated multiple times until you are satisfied with the improvements.
Document the changes you have made to the process. The documentation can be used to share with management on the improvements made and to train future employees on the proposed way of working.
If you click on the Charts button, you will see the following dialog box.
The system will automatically pick a title for your chart. However, if you would like to override that with your own title you can specify a title for your chart here. Note that this input is optional.
The system will automatically pick a subtitle for your chart. However, if you would like to override that with your own subtitle you can specify a subtitle for your chart here. Note that this input is optional.
The system will automatically pick a label for the x-axis. However, if you would like to override that with your own label for the x-axis you can specify a different label here. Note that this input is optional.
The system will automatically pick a label for the y-axis. However, if you would like to override that with your own label for the y-axis you can specify a different label here. Note that this input is optional.
The system will automatically pick a scale for the x-axis. However, if you would like to override that with your values for the x-axis, you can specify them here. The format for this input is to specify the minimum, increment, and maximum values separated by a semi-colon. For example, if you specify 10;20 then the minimum x-axis scale is set at 10 and the maximum x-axis scale is set at 20. If you specify 10;2;20, then the x-axis increment is set at 2. Note that this input is currently disabled and you will not be able to change this setting.
The system will automatically pick a scale for the y-axis. However, if you would like to override that with your values for the y-axis, you can specify them here. The format for this input is to specify the minimum, increment, and maximum values separated by a semi-colon. For example, if you specify 10;20 then the minimum y-axis scale is set at 10 and the maximum y-axis scale is set at 20. If you specify 10;2;20, then, in addition to minimum and maximum values, the y-axis increment is set at 2. Note that this input is optional.
If you want to add a few extra horizontal reference lines on top of your chart you can specify the values here. The format for this input is numeric values separated by semi-colon. For example, if you specify 12;15 then two horizontal lines are plotted at Y = 12 and Y = 15 respectively. Note that this input is optional.
If you want to add a few extra vertical reference lines on top of your chart you can specify the values here. The format for this input is numeric values separated by semi-colon. For example, if you specify 2;5 then two vertical lines are plotted at X = 2 and X = 5 respectively. Note that this input is optional.
If you click on the Verify button, the software will perform some checks on the data you have entered. A sample screenshot of the dialog box is shown in the figure below.
The objective of this analysis as well as any checks that are performed is listed in this dialog box. For example, the software may check if you have correctly specified the input options and entered the required data on the worksheet. The results of the analysis checks are listed on the right. If the checks are passed, then they are shown as a green-colored checkmark. If the verification checks fail, then they are shown as a red-colored cross. If the verification checks result in a warning, they are shown in the orange color exclamation mark and finally, any checks that are required to be performed by the user are shown as blue info icons.
Click on Compute Outputs to update the output calculations. A sample screenshot of the worksheet is shown below.
The text output displays the number of steps in the current process vs. the future process and the target percentage improvement sought using the changeover exercise. The analysis results contain the following information:
Pre: The amount of changeover performed before the start of the actual changeover (or internal activities). Ideally, we want to spend as much time as possible before the internal activities so that we can minimize the time during the changeover. The percentage change in the pre-time is also reported. An increase in the Pre-time from current to future is not necessarily bad!
During:The amount of time spent during the changeover during internal activities. This is the focus of the changeover reduction exercise. We need to make this time as small as possible in the future state. The percentage reduction in this time is compared to the target in the conclusion.
Post:The amount of time spent after the internal activities. We want to move as much of the internal activities to after to ensure as much reduction in internal activities as possible. An increase in the Post-time from current to future is not necessarily bad!
Total:The total time for the changeover which includes a combination of the pre-time, during-time and post-time. The percentage change in this time is also listed on the right.
VA Time:The total value-added time across all the steps is listed here. We would like to increase the VA time as much as possible.
BVA Time:The total business value-added time across all the steps is listed here. We would like to minimize the BVA time as much as possible.
NVA Time:The total non-value-added time across all the steps is listed here. We would like to minimize the NVA time as much as possible.
VA Percent:The value-added percent is the ratio of the value-added time to the total combination of VA time, NVA time, and BVA time across all steps. We would like to see an increase in the VA percentage time from the current state to the future state.
A graph that shows the split-up of the changeover time between Pre, During, and Post activities for both the current state and the future state. A GANTT chart of the activities for the current state and the future state is also shown. The green bars represent VA activities and the dotted lines represent the start and end of internal activities.
Here are a few notes regarding this analysis:
Always try to take a video of the changeover to assist you with the changeover analysis.
Make sure that the video does not alter the current state of working and captures "reality".
Use on-screen timers on the video to help you capture the time for various activities.
Make sure that you re-watch the video multiple times to ensure you are not missing any steps.
It may be a good idea to have the workers capture the video themselves as an improvement activity.
Use a cross-functional team to help with the identification of improvements and reward time for the same.