OTED as defined in the portal termwiki.com is “a setup reduction goal that reduces the process to a single step or one touch.” OTED is defined in the Encyclopaedia of Production and Manufacturing Management as “Setup times are non-value-adding activities. Lean manufacturing attacks setup times until they are reduced to zero or near zero. OTED refers to setup or changeover accomplished by the operator in one quick handling of the dies or tooling, usually in 10-15 seconds.” OTED, as defined in the portal leansixsigmadefnition.com, is “an exchange done with a single motion, rather than multiple steps and a changeover that takes less than 100 seconds and other references mention it is as being less than one minute.”
The principle behind OTED and SMED is the idea that the set-up time in a process is a Non-Value-Added step and leads to waste. It is based on the principle in the Economic Order Quantity and Economic Production Run models. In the Economic Ordering Quantity model, the Ordering Cost and the Inventory Holding Cost are balanced, whereas, in the Economic Production Run Model, the Set-up Costs and the Inventory Holding Cost are balanced. The main idea that comes out from both these models, is the smaller the Ordering Cost/Set-up Cost the lower will the Order size/ Production Run.
An important principle in Lean is the concept of moving from Batch Flow to Continuous Flow with the idea that moving from batch flow to single part flow to continuous flow reduces waste. Gradually reducing set-up times would gradually lead to smaller production runs which naturally lead to moving to smaller batch sizes and finally to a continuous flow.
Once this principle has been identified, it is the endeavor to reduce the set-up times in a process. At times continuous improvement kaizen steps are taken to reduce the set-up time and at times, entire DMAIC projects are dedicated to the reduction of the set-up time.
This technique is used in conjunction with Theory of Constraints and Value Stream Mapping with the identification of the bottleneck in the process, reducing the set-up time in the process till the time its cycle-time is less than the takt-time and moving on to the next bottleneck. In this iterative process, at first, there will be a need to use the SMED principles to release the bottleneck, however, after a few iterations further improvement of the process will only be possible through the application of OTED principles.
The Single Minute Exchange of Die is a changeover in a single digit, i.e less than 10 minutes, however, the One Touch Exchange of Die is a near-instantaneous changeover. This one-touch implies that the change can be done with a single motion rather than multiple steps. Implementing OTED is challenging and takes a process to the best-in-class process. It is however important to realize making just one step in the process as OTED may not necessarily optimize the entire process. At times a balance between a single machine with OTED capability and high operating and maintaining cost need to be considered as against dedicated, low-tech machines in a work cell layout.
References
https://www.velaction.com/one-touch-exchange-of-die-oted/
https://en.termwiki.com/EN/one-touch_exchange_of_die_(OTED)
(2000) ONE TOUCH EXCHANGE OF DIES (OTED). In: Swamidass P.M. (eds) Encyclopedia of Production and Manufacturing Management. Springer, Boston, MA . https://doi.org/10.1007/1-4020-0612-8_644
https://www.leansixsigmadefinition.com/glossary/oted/