Tuesday, September 3, 2013

SMED - Single Minute Exchange of Dies - An Industrial Engineering Innovation

SMED, Single Minute Exchange of Dies is an industrial engineering innovation, developed as a separate method or technique in the area of setting of dies. It was developed under the managerial initiative of Taichi Ohno, a Japanese engineer who appreciated the potential of industrial engineering for manufacturing companies and encouraged and challenged Shigeo Shingo, an excellent Japanese industrial engineer to his industrial engineering as well as engineering expertise to reduce setting-up time of dies.
Shigeo Shingo used process analysis, operations analysis, and motion analysis to come out with single minute exchange of dies system. It became a standard process and standard method to be used all over the world in various set up activities.
 Dr. Chao-Hsien Chu of  School of Information Sciences and Technology, The Pennsylvania State University, USA maintains a page on SMED. According to the page the procedure for developing SMED for a set up is:
  1. Form the setup reduction team.
  2. Conduct training and education.
  3. Study the setup process (e.g., use video tape).
4.    Classify setup operations into waste, internal setups (IED), and external setups (OED).
  • Waste - Operation which do not add values to the setup.
  • Internal Setups - Operations that can only be performed while the machine is shut down.
  • External Setups - Operations that can be performed without shutting down the machine.
5.   Eliminate the waste.
6.   Convert as many internal setups as possilbe to external setups.
  • Use standard insert module.
7.    Improve internal setups (include adjustment).
  • Use specially designed cart to organize tools.
  • Use quick-release fasteners instead of bolts and nuts.
  • Use stoppers to quickly position the jigs.
  • Use rolling bolsters instead of cranes.
  • Use overhang mechanisms to handle heavy jigs.
  • Use locating pins and holes (socket) to eliminate the adjustment.
  • Use standardized die height.
8.   Improve external setups.
  • Apply visual control principles.
  • Use checklist to avoid omission.
  • Use specially designed cart to help organize tools.
  • Organize workplace (5S) to reduce search.
9.    Develop the standard operating procedure (SOP).
10.  Evaluate the performance of setup reduction and do the fine tuning.
Observe the emphasis on waste elimination, the question of why do it here, and why do it in the present sequence.
These lines of investigation gave the ideas of internal set up and external set up.


9 minute video


A revolution in manufacturing: the SMED system

 By Shigeo Shingō,
Productivity Press, 1985


Case Studies

1. "Changeover Time Reduction Using SMED in a Manufacturing Industry: A Case Study" Rajdeep Singh, Dinesh Khanduja, and Upender Dhull, Udyog Pragati, Oct-Dec 2009, pp. 34-40

The case study is related to a piston manufacturing plant in India. The actual set up time was given as 260 minutes and it was reduced to 176 minutes. For calculating economic benefit only 50 minutes was assumed instead of 84 minutes of reduction. In 50 minutes of saved time, 78 pistons can be produced. There are four setups in month giving 312 units of extra production. The contribution from these extra pistons was calculated as Rs. 299,520 for the full year. The authors estimated that similar set up time reductions can be taken up on other bottleneck machines and the company can save Rs. 1.3 crore annually.

Some References

Wayne S.C., (2004), Success in Setup Reduction Efforts, Modern Machine Shop, Vol.77, Issue 1, pp.40-42

2. The Porvic-II separator plant die change time reduction

3. Reduction of the time utilized for the exchange of molds and preparation of the SACMI press in refractory bricks production.

The downtime for mold exchange for the SACMI press decreased from 200 minutes to 53.4 minutes. That is over 70% reduction!
The increased availability of the equipment represents a potential monthly cost saving of approximately $64,985 USD. The investment of the project was of $9,231 USD plus the time and labor of the participants.
 SMED projects represent a very important source of savings that can be applied to keep the Continuous Improvement effort going.

4. Glen Electric Ltd., Newry, UK - changeover of an 800T hydraulic press.

The data collected from the study was then analysed using gantt charts before all possible improvement opportunities were discussed. The reallocation of tasks enabled each of the operators to work simultaneously and without unnecessary walking around the press. The revised allocation was then put to the test with a resultant drop in Changeover time from 75 minutes to 45 min's.


Articles and Papers

Prerequisites for the implementation of the SMED methodology: A study in a textile processing environment
Author(s): Claire Moxham, Richard Greatbanks
Journal: International Journal of Quality & Reliability Management
Year: 2001 Volume: 18 Issue: 4 Page: 404 - 414 

SMED Implementation Step by Step
Knol Number 1904 ___________________________________________________________________________

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