I was recently visiting a large German factory that manufactures industrial equipment – huge mix, low volumes. When I first saw the site, sometime last year, it looked like a plane crash, with cells and half-completed product all over the place – not surprising for a high variety long process product largely managed by the SAP. The plant’s management team had tried to streamline their flow by Value Stream Mapping extensively, filling in wall sized brown papers with hugely complex flows, and with little shop floor progress. Since then, they have completely changed tack and started by focusing on preparing trucks to deliver on time to customers. This is inordinately difficult because of endemic missing parts, due to the huge variety and high work content of the product. But still, they’re trying hard. One consequence was streamlining the packaging line serving the truck preparation area. And then going one step further back to flow the assembly. A year later, the factory looks completely different, with a visible flow of products assembled to be shipped. OTD is up but missing parts persist.
Many missing parts are due to the complexity of scheduling machining and or foundry to get the right part at the right time. Because of the cycle time difference between assembly and machining, it would not make much sense to flow, so we need to pull. When they try to pull, they discover machining is not flexible enough, so: SMED. Interestingly the plant used to have a SMED program but simply did not know what to do with the change over time reduction other than improve OEE. Now they know: they need to reduce batch sizes drastically, and still have enough capacity to produce all prats needed. Change-overs are the pinch, and the plant feels the squeeze.
More fundamentally, what has changed is the management’s team perception of how SMED gains can be used for strategic-level advantage. Few top management teams ever get such a grip on lean thinking that they can see the direct link between basic shop floor practices and how to convert point-by-point progress into market-level benefits. Many instances of such thinking can be found in Art Byrne’s (of Wiremold fame) book: The Lean Turnaround. This is the critical skill needed at senior level to actually crack lean difficulties in the shop floor.
The answer to the question is pull! To be able to do so, two shop floor practices must be mastered: leveling the production plan and SMED, which is exactly what you already have in mind. In practice, pulling means that each press owns all the parts it produces, so get all the pressed parts out of the warehouse and stack them at the press – yes, yes, I’ve been there, it’s horrible, there is not enough room, etc. but, as with running, this is the pain barrier you must break (it’s what they’re working on in the German plant). Once each press owns its pressed parts, reducing batch size becomes obvious to press operators and managers alike. Once you get alignment between: 1) the business challenge – improve cash and customer satisfaction through lower inventory and better OTD and 2) the shop floor activity – make every press autonomous and owner of its production the link to 3) the kaizen activity makes sense to every one – SMED until we make every part every day, or every shift, it becomes much easier. Building this alignment is a question of focusing the management teal on going to the Gemba to visualize the strategic advantage succeeding at kaizen could give you, rather than using theories (VSM, ToC, 6 sigma, etc.) to try and solve the paper problem. In Art Byrne’s terms: close the parts hotel!