Quick Changeover/SMED System

What Is Quick Changeover and the SMED System?

SMED, an acronym for “single minute exchange of dies,” was developed by Toyota consultant Shigeo Shingo more than 50 years ago. At the time, Toyota was looking to reduce the inventory of automobile body moldings and began exploring solutions that would allow for more efficient changeovers. Shingo worked with Toyota engineers on a solution that ultimately reduced a four-hour setup into a three-minute process.

The basic idea behind Quick Changeover (or SMED) is that some setup activities can be performed while production processes are running (external elements) while others can only be done while machines are stopped (internal elements). To reduce time, SMED aims to convert as many internal elements into external ones, and from there, streamlines and refines each task in the process.

SMED is often explained using the simple example of how a NASCAR pit crew changes tires during a race. For those of us who don’t change tires very often, that process can take 15-20 minutes (if not longer), while a pit crew can change all four tires in a matter of seconds. Pit crews pull this off by performing as many steps as possible before the car stops for service, and uses a coordinated team to perform multiple tasks simultaneously.

Additionally, pit crews use a standardized process that ensures that they can deliver the same results during every pit stop and continue optimizing those standards to improve future outcomes.

The Definition of Quick Changeover

In manufacturing, changeover is a term used to describe the amount of time it takes to change out a piece of equipment from producing the last “good” piece in a production lot and producing the first “good” piece in the next lot.

Quick Changeover/SMED is a system that aims to reduce the time it takes to perform setups or changeovers. The primary goal of this process is to allow for more frequent changeovers, which increases production flexibility. While Quick Changeovers might help you increase production volume, it’s important to understand that that isn't the focus.

While Quick Changeover originated in a manufacturing setting and still uses a lot of manufacturing-specific terms, this methodology can be adapted to streamline processes in a wide range of work environments, from food services and healthcare to the financial sector and software development companies.

In non-manufacturing settings, you might replace the words “last good piece” with whatever term is used to describe a finished piece of work.

Advantages and Disadvantages of Quick Changeover

A successful Quick Changeover program provides organizations with several key benefits, including:

• Smaller lot sizes. Smaller lot sizes help organizations reduce lead times and eliminate inventory waste, which, in turn, lowers inventory carrying costs and improves cash flow.
• Faster time-to-value. Because Quick Changeover improves flexibility and shortens lead times, customers receive products/services faster.
• Improved equipment utilization. Shorter setups allow for more production time.
• Better production flow. Quick Changeover also enables heijunka or production-leveling, which helps companies manage unpredictable demand.
• Fewer defects. Quick Changeover can reduce instances of defects, resulting in less waste and fewer revisions.

While SMED is recognized as a powerful tool for streamlining internal operations, it’s worth noting that this methodology leaves little room for error. Equipment failures can cause the whole organization to fall behind and delay deliveries, resulting in customers looking toward your competitors.

How to Implement SMED/Quick Changeover

The SMED system focuses on making as many steps as possible “external,” and aims to simplify and streamline all tasks across both categories.

Let’s quickly walk through the steps of SMED to give you a better sense of what it takes to get started.

1. Document reality. First, you'll want to document your existing processes to establish performance benchmarks for driving improvements. We recommend recording processes for videos, as it makes it easier for teams to review the process multiple times—pausing, rewinding, and fast-forwarding as needed.
   
   
2. Separate internal and external tasks. The next step is to divide tasks into two groups: internal and external. Again, internal tasks can only be performed when machines are stopped, while external tasks can be done while machines are running.
   
   
3. Shift internal activities to external activities. Here, the goal is to accomplish as much as possible while machines are running so that when one production cycle ends, the next one can begin as soon as possible. Consider what activities can be eliminated or adapted so that more tasks can be completed while production is in progress.
   
   
4. Streamline external tasks. Next, you’ll want to look at your external tasks and identify processes that could be done more efficiently.
   
   
5. Identify parallel tasks. While this step is often excluded from SMED or Quick Changeover discussions, it’s critical for streamlining workflows. The idea is, two people performing complementary tasks can work a lot faster than one person working alone.
   
   
6. Streamline internal tasks. Whether the machine is down or you’re preparing to produce a lot, the goal is to find ways to get that process going as quickly as possible. Are there steps you can eliminate? Can you improve your workspace so that workers spend less time looking for materials?
   
   
7. Implement the new method. At this stage, your goal is to put new processes to the test. We recommend getting these practice runs on video so that your team has a visual tool for identifying and fixing weaknesses in the strategy.
   
   
8. Document new standards. Once you’re happy with the results, you’ll want to document the new standards.

Gemba Academy’s Quick Changeover/SMED System online training series will explain SMED fundamentals, benefits, and use cases. We’ll also walk through each of the eight steps of SMED, one-by-one. You can watch the first installment in this series for free to learn more about what’s included in this module.

Additional Video Content

• Learn What Quick Changeover & SMED Are in This 9 Minute Video
• Lean Tennis Ball Simulation with Practical Problem Solving & Quick Changeover

Blog Articles

New blog articles are published weekly. The following collection of articles are Quick Changeover focused.

• Online Training for Quick Changeover and SMED
• Quick Changeover and SMED for the Office
• Conference Calls, Kids, and SMED
• Real Life SMED
• Taking Changeover Time into Account for Takt Time Calculation
• 101 Kaizen Templates: Changeover Analysis