How to Implement Lean Manufacturing: Simplify and Solve – Setup and Changeover Time Reduction: Part 1
Before you read this post, take a look at this video. It’s related to our topic and…it’s just really cool. (You can start at the 30 second point. Then, watch closely because it happens quickly.)
I actually have more to say about “Value Stream Mapping and Team Problem Solving”, especially the “Team Problem Solving” part but I’m involved with a client that will soon be undertaking a focus on setup and changeover time reduction, so…I’m more interested in that right now.
In this post (and maybe the next one or two as well), I want to cover some general thoughts about the topic. First, this issue of setup and changeover time reduction goes by the misleading term SMED (Single Minute Exchange of Dies) in much of the lean literature. I don’t like that term for two reasons:
- Setups and changeovers may or may not involve dies,
- “Single minute” as a target is bogus in many cases.
My own term, as you’ve seen, is “setup and changeover time reduction”. I like that it’s comprehensive (i.e., it makes reference to both setups and changeovers and targets time reduction generally rather than some specific but artificial target) but it’s….long. I’ll shorten it to “quick change” in these posts just for brevity sake but you’ll keep in mind that we’re talking about both setups and changeovers and they won’t necessarily be “quick” (and certainly not “single minute”) even after “time reduction”, OK?
Second, it’s not every operation that needs to spend time on quick change. A past client is a well-known maker of high-end blenders. When the assembly lines “changed over”, new components were delivered to the lines and they just kept going. “Changeover time” was essentially zero. A beer-making client’s important changeovers were on the bottling line but that involved pulling beer from a different tank and changing the labels. Again, changeover time was near zero (so long as somebody remembered to get the new labels to the line in time).
In other cases, changeovers were important but were among the least of the client’s problems. A client that made take-out containers for restaurants changed the molds that shaped the containers but equipment downtime was much more of a problem.
My point is that quick change might not be an important focus for your lean initiative.
Clients of mine who’ve benefited from a focus on quick change have been in the materials shaping industries: metal stamping, roll forming, injection molding, and polymer extrusion, machining. These examples have in common the fact that equipment must be stopped and certain components of the equipment (e.g., stamping dies, extrusion tooling, injection molds) are removed, then replaced before a new product can be made. Further, the new components nearly always have to be tweaked and adjusted before a good new part is made.
It’s changed a bit in the last ten years or so, but my early experiences with quick change involved persuading operators…and supervisors…that setup and changeover time was at all important. I worked with a PVC injection molding plant that reduced changeover time substantially just by telling the setup technicians to stay on the setup until it was complete. The techs would remove a die, then go to lunch, help an operator who was having quality issues, help another setup tech with his changeover, stop by the lunchroom for a snack, then return to his own changeover. They weren’t lazy, it’s just that no one had ever told them that changeover time was important. The prevailing thinking was, “The press is down anyway…what’s the hurry?”
The manager of another plant in that company got into a heated (and public) discussion with the company’s CEO and President, claiming that changeover time in his own molding plant wasn’t an issue. (That plant manager was gone within a year.) Supervisors and operators who were smart enough to avoid challenging the CEO in a public setting were more than happy to tell me that his (and my) advocacy of reduced setup and changeover times was naive, if not altogether misguided. Others resisted less only because they misunderstood the importance of setup and changeover time. They agreed with the reduction efforts in that they saw the value in reducing any type of machine downtime. When I told them that the goal wasn’t to reduce downtime but to be able to do MORE changeovers, they sided with their skeptical colleagues.
What’s changed? Well, I think that quick change has just become accepted as part of the lean tool box. Further, there is that “critical mass” of stories and anecdotes as to how quick change makes a positive difference to a plant’s operations.
Here’s my own story that I use to illustrate the impact of quick change: At one of the plant’s I mentioned above, a PVC extrusion operation, a product run was measured in weeks. At that same plant, there was a fabrication department that used product off the extrusion lines and added bells to one or both ends and/or bent it into 45 or 90 degree angles. As a matter of fact, the sales of these fabricated products provided the plant’s real margin; the pipe was pretty much sold at cost so that there would be a customer for the fabrications.
Occasionally, in spite of the plant’s best efforts to plan production, the fab department would run out of a particular component. The fab supervisor would contact the extrusion supervisor that more product was needed.
In the days before quick change, the fab supervisor would be told that the product he wanted wasn’t scheduled to be run for another week and he’d have to wait for it. Everyone just accepted this condition as a “cost of business”. As the plant got serious about its quick change efforts, changeover time was reduced from several hours to about 30 minutes. At that point, when the fab supervisor let the extrusion supervisor know he needed more product, the extrusion supervisor would simply tell the setup tech to make the changeover and run whatever was needed, then change back to the original run. The two “extra” changeovers took less time than single changeovers had once taken. The benefits to scheduling, inventory management, to say nothing of customer service was apparent to everyone.
So…next time we’ll get into the “how to” of quick change.