- Review current status in changeover time for lead sites, identifying critical packaging lines in a key site and carry out a pilot exercise to significantly reduce changeover time.
- Establish a plan to identify and implement appropriate techniques – e.g. SMED (Single Minute Exchange of Die) system this is a set of techniques that make it possible to improve changeover performance.
- Check results and make improvements.
- Prepare roll out and training plans for other lead sites and potential suppliers.
Definition of Changeover
The time from the last product of one run until the first product of the next run at the correct speed and quality.
Some Concepts about Changeovers
- Line stops
- Run out old product Remove old packaging
- Clean down line
- Remove old change parts
- Repair and maintain new change parts
- Fit new change parts
- Deliver new product to line
- Load new packaging materials
- Run-in adjustments
Basic principles for quick changeover
- Development between internal (machine needs to be stopped)and external(machine can be running) adjustments
- Transform internal elements to external
- Streamline the other internal elements
- Streamline the external elements
- Based on figures presented in your internal benchmarking studies it is possible to identify some “gaps” in current changeover time.
- The elimination of these gaps will produce significant benefits in terms of availability and flexibility.
Methodology – Overview
- SMED originated in Japan in the early 50’s
- It was developed by Shigeo Shingo at Toyota
- Single means single digit < 10 Minutes
- It was first used in the car industry to allow fast Exchange of Die in body panel presses
- It helped Toyota cut the time it took to change a large body panel press from 4hrs to 3 minutes
- Flexibility – Meet customer needs without the need for excess stock.
- Quicker delivery – Shorter lead times means money is not tied up in excess stock.
- Better quality – Reduced setup errors.
- Higher productivity – Shorter changeovers reduces downtime, which means higher efficiency ie OEE up!.
Basic steps in a typical set-up
- 30% Preparations and clean-up
– getting mat. parts and tools and check function
– remove mat. parts and tools and clean up
- 5% Mounting and removing of parts
- 15% Measurements, settings and calibrations
- 50% Trial runs and adjustments
Why do set-ups take so long?
- Internal and external setup are confused
– Internal set-up: machine must be stopped
– External set-up: can be done while running
– Many tasks that could be done while machine is still running are not done until the machine is stopped
- Set-up is not stream-lined
– No standard of who does what when
– No parallel working
– Tools, parts far away from line, difficult to find
– Many parts to mount
– Many difficult settings which require adjustments
Economic order quantity model
- Assumption: Sales are flat and continuous
- More smaller orders to factory results in:
– Lower Stock Level, Lower Stock Carrying Cost
– Higher Set-Up Cost, Lower Maximum Capacity
Parallel working analysis
GANT chart used to synchronize and balance the set-up activities done simultaneously by 2 operators.
Change Over Time Study – Analysis
- Large machines often involve a lot of movement between elements of the set-up
- This excess movement wastes time and effort
- Think about the movement of the person doing the set-up and try to document the most logical sequence for the operation.
- Develop and implement a procedure for efficient working
- Consider using more than one person for the change
– each person follows a fixed procedure
– built in (safety) signals to synchronize activities
Change Over Time – Target
Advance preparation of operating conditions
- Get the necessary materials, parts, tools and conditions (temp. pressure) ready BEFORE set-up begins
– Check gauges
– Put items in right positions
– Build temporary holders
Implement standardization function
- Decide which functions can be standardized
– standardize outside dimensions, fittings, settings so that parts can be exchanged easily
- Try to replace fewest possible parts (zero!)
A die performs 2 functions:
- Apply mechanical pressure
– can be standardized
- Form product
– is unique for each product
Least Common Multiple
- Change function by making a setting
– Leave mechanism in the machine and just modify its function by setting
– Make settings NOT adjustments
- Agree proposed recommendation and establish a pilot project.(Identify benefits upfront)
- Establish a plan to implement adequate techniques – as suggested the SMED (Single Minute Exchange of Die) involving Operational Excellence Team
- Check results and make improvements
- Roll out , as a best practices, for others lead sites (can also consider working with suppliers!)