What is SMED in manufacturing? Single-minute exchange of die

 What is SMED?

Single Minute Exchange of Die (SMED) is one altogether the  lean production device for reducing waste during a manufacturing procedure. It offers a quick and efficient way of converting a production manner  from one product to  subsequent product. This fast changeover allows us to scale back production lot sizes and thereby enhancing flow . The term “single minute” does not mean that all exchanges and starts-up will take only one minute, but that they should take less than 10 minutes (i.e.“single-digit minute”).

Basic of SMED:

In SMED, changeovers are made from steps that are termed “elements”. There are two types of elements:
★ Internal Elements (elements that has got to be completed while the equipment is stopped)
★ External Elements (elements which will be completed while the equipment is running)

History of SMED:

★Developed by Shigeo Shingo
★Dr. Shigeo Shingo is known as the father of SMED
★ Developed within the late 1950

Why Use SMED?

SMED is employedd for:

(A) Large Lot Production Waste

Large batches are produced to scale back the amount of ‘changeovers’ as setup times are usually long leading to:
★ Overproduction and Excess Inventory (unsold product, raw material and work-in-progress).
★Waiting Time (customers await entire batches to be complete, instead of just what they have now).
★Defects (storage risks damage and deterioration of product).
★ Transport/Motion (can be suffering from the necessity to manage large batches of raw material, WIP or product.

(B) Changing Customer Needs

Customers are searching for an ever-increasing kinds of goods that are available if they want them     (diversity of goods not mass production). The life cycles of goods are shortened as creativity becomes a key factor. Shorter timescales are needed in both the design/ development process and in production to accommodate these needs

(C) The Concept of Time

★ From a logistical standpoint, a corporation looks to deliver On Time In Full (OTIF) to customers.
★ Economically, it's advantageous if process  time interval or the duration required to supply the product is short/brief.
★Many time-consuming activities, however, don't  add value to products.
★SMED can facilitate the removal of NVA (in set-up) or at least make sure that necessary NVA activity occurs concurrently with VA activity.

 Steps to reduce Changeover:

There are seven basic steps to reducing changeover using the SMED system:

1. OBSERVE the approach in question. .
2. Separate the practices of INTERNAL and EXTERNAL task activities . Internal activities are those that can only be done when the process is halted ,while External activities are often conducted during the last batch or when the subsequent batch has begun. For example, starters go and get the necessary tools you need for the on job.
3. Convert (where possible) Internal processes into External ones  (a good example of this is machine preheating).
4. Simplify and Streamline the remaining internal operations. Emphasis on fixation. Shigeo Shingo found it’s just the last turn of a bolt that tightens it.the rest just it movement.
5. Streamline the External operations,to the same degree as the internal ones.
6. Report the latest process, and acts yet to be done.
7. Do it all over again. A 45 percent increase in set-up times should be required for each  iterations of the above cycle so it'll take several iterations to cross the ten-minute mark.

 Implementation:

Shigeo Shingo recognise eight techniques that ought to be considered in implementing SMED.

1. Separate internal from external set-up operations.
2. Convert internal to external setup.
3. Standardise function, not shape.
4. Use functional clamps or eliminate fasteners altogether.
5. Use intermediate jigs.
6. Adopt parallel operations.
7. Eliminate adjustments.
8. Mechanisation.

Stages of SMED improvements:

External set-up can be done without the line being stopped whereas internal set-up requires that the line be stopped. He suggests that SMED improvement should undergo four conceptual stages:

A. Make sure that external set-up actions are performed while the machine is still running,
B. Separate external and internal set-up actions, make sure that the parts all function and implement efficient ways of transporting the die and other parts.
C. Convert internal set-up actions to external.
D. Improve all set-up actions.

 Benefits:

★ Flexibility – without the necessity to carry stock.
★ Quicker delivery – reduced  time interval and customer waiting.
★ Improved quality – less storage related defects.
★ Greater equipment productivity – shorter downtime and changeovers (linked with OEE, overall equipment effectiveness)
★ Smoother start-ups (standardised changeover processes improve consistency and quality).
★ Lower manufacturing cost (faster changeovers mean less equipment downtime).
★ Lower inventory levels (smaller lot sizes result in lower inventory levels).


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