"SMED" By Step Deployment

SMED (Single Minute of Exchange of Die) is the methodology of changeover time reduction.

Basic Concept of Changeover

?Establishing excellent system for “many kinds + small lot” production by not only improve changeover time, WIP( work in process), Lead Time reduction but also losses improvement of adjustment, quality defects, re-work etc.

If we improve time/changeover, we increase frequency of changeover, and apply;

Big lot production à Small lot production à Producing only customer required à Products cost reduction.

?We can identify a lot of losses by reduction of inventory.

?We improve Overall Production Line Effectiveness by improvement of changeover time.

?We can expect high margin without investment for new equipments.

What is “Internal Changeover” and “External Changeover”?

There are not specific method of “Internal Changeover” and “External Changeover”

Internal changeover is the jobs that is done during machine stop (downtime). And external changeover is the jobs that is done without machine stop.

Therefore, we can reduce downtime by improvement of Internal changeover. In order to improve, we need to modify the jobs from internal to external.

Changeover Improvement

Changeover improvement is to minimize its time, “How do we prepare perfectly in advance” and “How implement change and adjustment by short time without problems”.

Step Deployment

Step deployment and time reduction

1st Step: Loss Identification

We define the actual changeover loss in this step. I suggest you start to identify actual changeover loss time. That is why, this is “check” for improvement motivation. Changeover is loss that this do not produce added value. We need to know actual damage and the necessity of changeover improvement.?

First action is to identify damage from changeover loss on Effectiveness.

I am sharing a loss identification example.

Changeover is loss that do not produce added value. Let’s think about doing it within 10 minutes. However, it may be impossible to improve it less than 10 minutes by short period. Therefore, set up target to reduce 50% at first time. If you continue “50% improvement” by step by step, you achieve “less than 10 minutes” in the future.

For example, at the case that you spend 60 minutes for changeover, if you improve it by 3 times, you can achieve “less than 10 minutes” (60?30?15?7.5 minute).

Set up target to improve 50% of changeover time at first.

2nd Step: Observation of changeover jobs

Observation of changeover jobs is done by jobs procedure and its time study. We can use digit video recorder to record the jobs. Benefit of video recording are that we can observe many times, we can study more details by low-speed, and we can discuss by teams.

Make job study chart. Define “Job” one by one according to function and element. Identify time for each job by checking video. We need “preparation” for changeover job observation.

I am sharing a Job Study Chart for Changeover example.

Show jobs process by flow diagram (spaghetti diagram) on lay-out. This chart is useful for finding MUDA, combination of few workers, and making improvement ideas of lay-out.

We classify jobs to “MUDA” “Internal jobs” “External jobs” in order to find out improvement ideas. We need to find MUDA at first. MUDA is “Looking for something” “Walking” “Transportation” etc. Secondly, we classify jobs to “Internal” and “External”. If we can improve “internal time”, we can reduce downtime. Therefore, we try to modify jobs from “internal” to “external”. In order to do this action, we need to know what kind of “internal” and “external” jobs are done.

There are 3 purposes at changeover jobs.

1. Preparation/Clearing jobs

2. Exchange jobs

3. Adjustment jobs

“Preparation/Clearing jobs” are preparation jobs, clearing jobs, cleaning jobs and MUDA jobs that is found at observation. “Exchange jobs” are disassembly, assembly and exchange of die, jig and tools. “Adjustment jobs” are alignment adjustment, setting as standard, inspection, production trial etc. We feel adjustment is necessary. Therefore, we can accept only one time. But, from 2nd time, we need to define that is loss. After classification by purpose, those information is described by matrix.

3rd Step: MUDA Elimination

In this step, we need to investigate improvement idea to eliminate MUDA extensively according to the observation. It is important when we improve, we start to think about “E” “C” “R” “S” method. This method is useful at each step. Let’s start to think about “Eliminate” about MUDA.

Principle-1 ECRS

-Eliminate

?Start to think “don’t do unnecessary job.

-Combine

?Combine jobs together if “eliminate” cannot be done.

-Re-arrange

?Investigate Re-arrange job flow/process about “when” “How” is better.

-Simplify

?Simplify for more easy.

Principle-2 5W1H

1. What? Why?

What is purpose? Is there unnecessary thing or change?

2. When? Why?

When is it done? Possible to do it together? Possible to change flow?

3. Where? Why?

Where is it done? Possible to do it at same place or other place?

4. Who? Why?

Who do it? Possible to do by one person or other person?

5. Which? Why?

???For one direction? No return?

6. How? Why?

How do it? Possible to simplify?

Never ask the "why" question!

According to ECRS and 5W1H, E is for What. C&R is for When, Where and Who. And S is for How.

Elimination MUDA of search

“5S”, “3 fixed” and “control cards” are basic concept for MUDA elimination.?

-2S (SEIRI, SEITON)

SEIRI classification to necessary/unnecessary and throw the unnecessary to disposal.

SEITON Replace for easy use of the necessary.

- 3 Fixed

Fixed position ? arrange replace position

Fixed goods ? arrange replaced goods

Fixed volume ? decide volume

Use control cards for anyone to know normal/abnormal.

Example: Fixed position at rack

Elimination of MUDA of transportation

MUDA of transportation is related to MUDA of looking for. We can expect some of MUDA of transportation is improved by elimination of MUDA of looking for. In order to transport Jig, tools and parts together, it is better to make exclusive portable car. Investigate place of jig, tools and parts where is possible to access by less than 5 walks during changeover. However, at the case of big machine or combined line, transportation is huge. In this case, one idea is to do changeover by few people. We can reduce 50% if we do by 2 person simply. Elimination of MUDA of looking for goods is effect to improvement of MUDA of transportation.

4th Step: Classification of Internal/External, and modification from internal to external.

At first, we define what is internal and external. And secondly, we modify internal to external in order to improve machine downtime. If you had not improved changeover, in the past time, definition of internal/external may be not clear. Therefore, you may find huge changeover loss. If we think positive, we may be able to get big benefit from the improvement. Changeover improvement is perfect preparation.

Main improvement of modification to external is scoped on preparation. Generally speaking, there are a few jobs that need to stop machine during preparation. If you have preparation job during changeover, let’s modify to external extensively, and get effect that you can reduce internal time.

Key points to improve to external are;

-???????Do we need this job during internal job truly?

-???????How we can improve to external job?

Let’s check the above key points on each jobs, and put out ideas.

Preparation must be done in advance. Do not look for, Do not transport, Do not choose. Clearing must be done after machine start-up. Internal should be thought by “in advance” or “after running”. This concept is “R”.?

Concept of “Exchange” ”Adjustment” to external is almost same as preparation.

Possible to modify by off-line?

Possible to modify pre-set?

Possible to adjust in advance?

Possible to replace close to machine?

Possible to do it near to machine?

Please investigate “To External”. “Exchange” “Adjustment” should be thought by “in advance” This concept is “R”, too.

5th Step: Improvement of internal jobs

Until this step, core jobs of internal like exchange, adjustment are remained. But find loss should be improved even if core jobs. Scope of internal jobs improvement is “exchange” and “adjustment”.?

Improvement concept is “Easy to do” for all taking off parts and assemble jobs.

1. Improvement of taking off

Implementation of this improvement is to check all jigs, tools and fasners should be improved like;

-???????Can reduce number of bolts?

-???????Can modify without bolt, spanner?

-???????Can reduce type of bolts, tools?

-???????Can do it at one place?

-???????Can modify height of bolts?

Exchange job improvement should be thought by “Can reduce?=C)” or “Can do easier?=S”.

Divide role and concurrent job

At the cases of big machine or line, workers have to change at up/down, front/back frequently. In order to improve walking loss, please decide roles of each worker by few workers. And, if few workers do changeover, internal time is reduced rather than one worker. Concurrent jobs aim is it.

Key points of exchange improvements are;

1. Easy to take off/on

2. Clear job role and concurrent job

Improvement of adjustment is “elimination of adjustment” Why adjustment happen? That is why, due to poor set up standard and loss to re-try. If we set up good setting standard, we may eliminate adjustment.

1.Standard integration

We investigate the possibility to integrate even if products is different. If it is difficult, use block or spacer for easy adjustment.

2. Positioning improvement

After standard improvement, investigate on “How to set up by one time by using guide, block and pin”,?“one touch set up”, and “Elimination to measure”.

Adjustment improvement is elimination of adjustment. Elimination of adjustment is focused on standard setting.

One shot fixing by using block gage

Setting of attachment guide

6th Step: Improvement of external jobs

By now the focus was to reduce the equipment stoppage time. Once we proceed to this point, operation process needs to be concerned. Previously, internal was brought to external with losses. So there are losses still in external. Then the Reduction of External is necessary. Not only equipment stoppage, but reducing overall changeover operation process.

The key to improve efficiency of external operation is to analyze external operation, and eliminate the losses based on the analysis.

Example of unnecessary moves

Think the necessary operation as

E=can not stop

Next C= try to reduce

Next S=make it easier

7th Step: Standardization

Executing Kaizen (improvement) is the first priority, and also very important thing is to sustain the result. The achievement of Kaizen will be meaningless if he achievement disappear when the time goes by. So what is needed is to standardize the Kaizen and make people be able to repeat the action.

Following is the procedure to standardize and sustaining of changeover:

1 – Creating operation procedure and standard instruction

2 – Carrying out the training

3 – Creating mechanism of sustaining

Please work hard.