OTED

OTED - One touch exchange of a die

Really closely related to SMED - OTED means that changeovers are reduced so that they can be performed in a single step (one touch). It is slightly different to SMED but more difficult to implement.

Depending on your field of industry the defined times to perform a changeovers varies between 1.5 and 1 minute.

To run OTED successfully following actions are required upfront:

• Reduction of adjustments needed down to zero

• No fastening with screws needed

• 100% positive locking between die and tool carrier

• Proper fitting methods

• Separation between tooling and function

The target is simply explained: The exchange of a die is done with one single motion.

When having a look at the development of improving changeovers the first step is to implement the single-minute exchange of a die (SMED). SMED helps you in the beginning to figure out how to perform the changeover with less motion. OTED is then the high level of changeovers. As mentioned as SMED can be also understood as single digit exchange of a die, yes this means everything under 10 minutes is SMED, OTED stands for the ultimate target. Through continuous improvement actions on SMED you are striving to reach the state of being able to exchange tooling in the takt of your line with one single motion.

In the end with OTED you have to deal like with all the other Lean Tools, don’t just apply it to be cool and “lean”. If it doesn’t make sense for your operation or process don’t do it. But when you decide to strive for OTED and you and your team are convinced by the promised improvements , make sure to understand the process flow first then take action.

SMED

Single Minute Exchange of a Die

This series of techniques was invented by Shigeo Shingo to set-up manufacturing equipment in less than 10 minutes. Most of the time people think in one minute but is thought as single digit minutes.

So what is behind the set-up time reduction?

This method is driving to increase the net production time as much as possible by minimizing the needed time to change from one model to another. As far as you have two or more products running on your line or to simply exchange parts of your machine or equipment that regularly needs to be replaced. This is increasing the flexibility of your production and allows you to react on changes in demand more quickly.

When trying to reduce changeover tomes the typical goal is to reach less than 10 minutes. The short summary of SMED activities is to analyze each element of the changeover with the EMIPS method to see if it can be eliminated, modified or moved outside the process, integrated, tasks are parallelized or synchronized.

SMED

When looking at those three stages we can simplify it further for each stage:

Just ask yourself:

Separate:
Can this task, as currently performed, be done while the line is still running?

Convert:
Which process steps can be moved out of the changeover itself and be parallelized or completely taken out? How can you do it?

Synchronize:
How can the remaining tasks be synchronized so you need as little time as possible to complete the changeover?

I save you the story with the pit stop in formula 1 - just google it by yourself and you will find the evolution of pit stops. Quite interesting and still valuable.

So what are the benefits of SMED?

The first effect you will see on improvements of the OEE of your manufacturing facility. If this is important for you and you are numbers driven. In the end you will reduce downtimes and therefore manufacturing costs as your machines will have a greater net operating time.

With a long term perspective SMED will enable you to have smaller batch sizes, which will improve your possibilities to react faster on changes of customer demands and in addition your inventory (tied capital) and WIP (work in progress) will decrease.