An excellent workshop by Mary and Tom Poppendieck today entitled “Stop Thrashing: Pull Schedule Techniques for Level Workflow”. It really left me buzzing, for two reasons. Firstly, Mary talked about her real experiences implementing a kanban system at 3M which was fascinating, and secondly, I ended up being invited up to the front to share my experiences with implementing a kanban system at Yahoo!
Mary described how 3M moved from an MRP (Material Resource Planning) system which was software based and delivered 60% against plan, to a kanban system which was physical token based and delivered 95% against plan. The reason it worked was that ultimately, the system was designed by the floor workers who operated it – not by management – so when there were problem, the flow workers understand how to solve them. To quote Mary, “Computers destroy our capability to schedule”.
The key to a kanban system working is what Mary called ‘setup time’ – the time to get the system ready for production. A large setup time means that there need to be large batch sizes to be economically viable, whereas a small setup time means that batch sizes can be smaller. The smaller the batch size, the more just-in-time is possible, and the better the flow. Setup time for software is generally the merge/test/deploy process and this matched my experience. At Yahoo! we had a release cycle of one week, because that was how long the release setup time was. Reducing the time needed for the release process by employing more automation (e.g. testing) would have enebled us to release even more frequently. One of the goals for a lean manufacturing organisation is ‘single digit setup’, or a setup time of 9 minutes or less. Mary described a visit to a Toyota factory where the setup time was so small that they were able to achieve a batch size on one – each car in the line was different.
Mary also talked about Building the Empire State which was built in recored time (20 months from the start of the entire project) at a rate of one floor a day. The bottom floors were being built before the top had been designed by using a number of techniques:
- Collaborative teamwork between the owner, architects and builders
- Deigning such that construction was quick and easy (as opposed to cheap)
- Breaking dependencies so that elements of the building could happen in diffierent orders
- Focussing on the constraint to enable a flow of material
- Eliminating waste – for example having restuarants on the buildng during construction
In the afternoon I ran an OpenSpace session on kanban which had around 15 people come along to and I did a quick run through of my latest KFC slides. There seems to be a real growing interest in the community about these new ideas, and I think the explanations and understands are gradually becoming clearer.