Let’s talk about SMED.
Single Minute Exchange of Dies (SMED) is the philosophical approach to changeover that says “What do we need to do to make this changeover happen in under one minute?” Odds are good that the one minute changeover is impossible, impractical, or unaffordable – but that doesn’t change the philosophy. The goal, the direction in which we incrementally step, is to get ever closer to that one minute limit.
One of the easiest and most affordable first steps in this direction is a dedicated set of tools for the change. All it takes is for one tool to be on walkabout and the technician loses precious time searching for a number 2 Philips screwdriver or a pair of diagonal cutters. In terms of cost, a technician walking around while the machine is not operating – especially if the machine is a constraint – is huge. The cost of a constraint piece of equipment is the equivalent cost of the entire company’s revenue every minute (refer to Eli Goldratt’s “The Goal”). Seems like a small problem until you take that into consideration.
The set of tools isn’t just a toolbox with tools in it. Let’s say you need to change over a tablet press or a stamping press. There are eleven tools you need to have on hand, and the time to find out that any one of these tools is absent is BEFORE you need to changeover. That means that before you begin, ideally before the machine is finished its last run or cycle, you know if all the tools are there. If the box is just a box you need to a) find the box, b) open the box, and c) check each tool in the box. If the box was not a box but was something your grandfather had in his garage – a shadow board – you would know at a glance if any tool was missing. The shape where the tools should be would be empty, a clear warning to you that your search for the tool has just begun.
The argument for rolling toolboxes with every conceivable tool is fine for facility maintenance folk or repair technicians. We are not discussing those roles at this time – we are looking at the technician or the team member who has to switch a particular machine from one function to another and do it fast. This is not a call for “more is better” – more is confusing. If you need eleven tools and you have a box with a few hundred tools you now spend time looking for just the right tool. The 5S approach is very helpful here. The first “S” – Sort – removes those things that are not required and ensures those things that are required are present. Use this approach with the tool board. This also might mean you need two of a particular tool, like a vice grip plier. Or a 3/4″ box wrench.
Maybe what is needed is multiple boards. Consider an assembly line for building a device like a cellphone. Each station needs specific tools – not every station needs the same tools. Each position would have the tools that operator needs. Now apply that same notion to a packaging line. The filler would need changeover tools, the conveyor belt has a specific set of tools, the labeler has a set of tools – you see where this is going. If every station has what it needs to changeover and the whole line team is trained to participate in the changeover the pace can be surprising. Consider your team as a potential NASCAR team getting the equipment back on the track in record time. This is where the 5S approach comes back – the second “S” – Set in Order – suggests not only should each position have the tool needed right next to it, but also the tools should be on the board in the order they are needed. And once more, this might mean more than one tool. Assume a fill station needs a #2 screwdriver to remove the main panel, then a plier to remove the line clamps, a socket wrench to remove the pump, use the same socket wrench to attach the clean pump, use the pliers again to replace the line clamps, and then… where did that #2 screwdriver go? The cost of a screwdriver is meaningless against the cost of time to go find another one.
Once the boards are setup, consider 5S again. Third “S” – Shine – is to make the board not only look professional and intentional, but also to label it so anyone know what goes where. You might use a picture – you might cover the entire back of the board with a cool laminated image of the board with real tools on it – in black and white of course, so the real tools stand out.
While we’re on the 5S path let’s consider Standardizing, the fourth “S”. Make it easy to spot the tool board – all the boards should be similar in some way (color, signage, etc.) so new operators can easily spot the board. Color is the easiest, along with position. Size can be tough – some boards just need a lot of tools, some need one.
Think of the value a team can gain from a clean, dedicated set of tools for each particular area of a process. The stress of finding the right tool or the dread of having to figure out a new way to “jimmy” those two clamps together vanishes. The team has less frustration, the process gains some breathing room, and you know it will be repeatable. Oh, wait – we missed that last “S” – Sustain. Unless the team “gets it”, understands that the change will be lasting and beneficial, the change will not remain. Walk through everything with the team – talk to them. Maybe they have some suggestions you missed; after all, they are the experts. Make sure the solution works for the team, not for the manager. If this becomes something that requires handholding, or worse becomes a target for sabotage (I just ‘borrow’ a screwdriver from that board – there’s always one around somewhere) then the board can become a problem unto itself. Sustain is not the enforcement of the rules, sustain is the universal agreement and understanding of the benefit of the change. If everyone sees the benefit then everyone will naturally help keep the change in place.
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