It seems that lean these days is all about learning and coaching. What about the good ol'-fashioned just-in-time stuff of the earlier days?
Dear Gemba Coach,
It seems that lean these days is all about learning and coaching. What about the good ole-fashioned just-in-time stuff of the earlier days?
Touché – and I plead guilty. The other day I was on the Gemba of a plant that makes industrial equipment and had exactly the same discussion with the plant manager. This fellow has an excellent, intuitive grasp of respect and a deft touch with people. He’s really good at getting people to work together and has a gift for fostering both change and goodwill. But his corporate management is asking for immediate productivity results, by the book and by the numbers. Hmm.
Now, in a low-volume high-variety business run by an MRP, quick productivity results are hard to find. There is no high-runner cell with ten operators that can be quickly kaizen-ed down to five. There are a lot of grinding, turning, milling machines, a monument of a paint shop, a few craftsmen-like assembly stations, and many operators milling about according to where the supervisor needs them. Not surprisingly, on-time-delivery is a struggle, and productivity is poor. This is not seen as a problem since the margins per product are high, but we all know what senior execs are like when it comes to productivity figures (and their own bonuses).
To make matters worse, in a high-variety environment, any increase in volume means an increase of one part or component missing, which requires a schedule change, leading to less OTD and productivity … so we won’t be saved by volume. That sucks. The strategy then, is to ship on-time-as much as possible, in order to get cash in hand from the customers and pacify corporate with cash and bottom-line. But how?
Not with Safety Glasses
We need to look at the same situation with several different pairs of goggles. One, the respect glasses, reveals how everything we ask operators to do that does not add value or does not contribute to shipping products is a lack of respect. Guys are here to work, not to fill in paperwork or recount kanban cards. The more focused their work, the more productive, and the more likely we are to ship on time. But how can we focus on the right problems?
We use the other pair of glasses: the just-in-time system, and a view of the entire factory as if it was a mechanical engine. We were looking at the value-stream maps his team had been doing, and they had the usual flaw of detailing the material flow and sketching the information flow as an afterthought. Value-stream mapping (VSM) is part of a lead-time analysis, not a process analysis. So two critical aspects of VSM are:
- The number of references made on each machine, since production lead-time is calculated as the time between the last part of A from the previous batch to the first part of A from the next batch (with batches of B, C, D, etc. in between).
- The frequency at which information is updated in the information flow: once a week? Once a day? Every hour? Whenever something happens, and so on.
The main problem of a high-variety environment is that although everyone is busy working, they’re usually working on the wrong part. As we walked the shop floor we checked the work orders: either ahead (parts needed for next week, aka overproduction), or late (parts needed yesterday, aka waiting). So we tried to look at the production process as a dynamic system of information converted into action, and then into parts. What tells who to make what when. The more frequent – and the more regular – the update, the better chances of making the right stuff at the right time.
Want Fries with that kanban?
Developing the dynamic vision of just-in-time is by no means intuitive, and it requires learning the techniques and discipline of a pull system. For instance, they’d set up a vague form of kanban with a launcher that had many, many cards in it. Now, any restaurant works with kanban. The front waiter takes the orders when people sit down, and then puts them in front of the cook to make in the same order. The cook picks up each order and either (1) it’s a today’s special so she takes it from the supermarket of ready dishes or (2) it’s à la carte and she makes the dish from scratch. Then it’s shipped. Like a complex product, a table has to receive several different dishes at the same time, but hey, restaurants mostly get it right – so why not factories?
Back at the Gemba we looked at the launcher and we calculated that the machining team had orders for the next three days. This is massive overproduction of information, and leads to a number of problems. First, how likely is it that the kanban cards of three days in the future truly represent what will really be needed then? Secondly, with three days of cards ahead of you, how tempted would you be to pick and chose the ones you feel are urgent, or easier to make? Thirdly, and this is where just-in-time dovetails with involvement and engagement, with three days of work ahead of you, how determined would you feel to get the work down rather than have another smoke before changing the tool setting once more? How involved would you feel with the company’s determination to ship to its customers?
There is a sly underhand trick to pull: it completely changes frontline management’s job. The supervisor can no longer decide what to do when; she’s got to follow the cards, just like the cook. The supervisor must now focus on doing the job right, much like the cook again. Some supervisors will love it, feeling liberated from self-defeating decisions, and some will hate feeling technically challenged and losing petty boss’ power.
Furthermore, this also means that information management and material handling is taken away from the operators’ job and given to a specific logistic function: the train that delivers parts and picks up cards, cards which then need to be sorted and redistributed. When this happens we suddenly realize quite how many tasks operators have to perform that have nothing to do with making parts.
The difficulty, of course, is to walk on two feet – to hold the two different visions – just-in-time and respect-for-humanity – at the same time and slowly learn to figure out how they converge. This was, I believe, already the point of the very first paper on lean published by Toyota veterans back in 1977, although at that time much of the paper was devoted to calculating kanban cards. We’ve learned the hard way that respect is as important as kanban, but maybe we’ve now overcorrected. Without both a system-level and card-level understanding of JIT, respect becomes wishful thinking and will not satisfy any of our stakeholders: neither the operators (we’ll “respect” them on the wrong topics – they’re not fooled that easily, involvement comes from sharing the company’s objectives) and neither corporate. Never easy, but let’s face it, never boring either!