After learning the theory of Lean manufacture on day 7 it was time to put it into practice, this meant playing with Lego. The reason for the Lego was to demonstrate the difference between a ‘push’ style of manufacture, a traditional style of manufacture, and ‘pull’ style developed through Lean manufacture. A simple metaphor to explain what was to come is try and pulling a piece of string versus pushing it.

Push

The group was set up into stations that performed various stages of manufacture, with a forklift driver to deliver the parts (Lego blocks) around the factory. We initially calculated how long each part would take to manufacture then factored in various other industry standard costs, then added transport time and came up with total build time for a batch of ten. This time of around 2 minutess would be used to send new orders into the “factory”. The first order hit the factory, brimming with confidence the group started the first batch. Quickly the wheels began to fall of the production process. Stations were quickly running out of stock, only 1 out of 5 workers were busy at any time, and the poor forklift driver was going non-stop around the factory. Six minutes into production we had got our first batch through to the customer, that made us three minutes late on our first order. Quickly production was stopped due to the customer pulling orders for lateness. From there we had to count up the cost of this production failure. After the first production run we had around £150 of product left on the floor.

For round two we were able to change two things. As a group we decide to rearrange the production line so the was shorter distance to travel. We also changed the stocking system so the forklift driver was working more effectively. The calculations were run again on the new setup and with the reduction in transport time we had a new lead time of 90 seconds, easy. The first order was in and instantly we knew the changes hadn’t made as much difference as we had first hoped and to make it worse the first batch was scraped due to a defect. After 6 minutes and two delivered batches the production was canned again. Despite getting one more batch out, albeit late, the resulting stock and defects left in the factory added up to around £600, whoops.

These two production run-throughs clearly outlined the they problems of the “push” system, too much stock on the line and inefficient production processes.

Pull

This new system saw complete change in thinking when it came to manufacturing our Lego blocks. We went from producing batches of 10 to producing 1 part at a time on a line that could be stopped and started with little delay. The stock ordering had also been outsourced and was now delivered directly onto the line. Lastly the forklift had gone because single parts could be moved manually between stations — because the batch size had been reduced. We ran the calculations again and a new time of 55 seconds was set as the lead time for a batch of ten.

After our last attempts we didn’t hold high hopes of getting close to this time. The first order was in and the rhythmic sound of effective production took over the room. Our first batch took 50 seconds and subsequent batches weren’t far behind. Once the line was stopped there was minimal stock left on the line, most still being held at the third party suppliers: success!

Analysing the old method and reducing the 8 waste streams had paid off. Transferring these methods into real life results would mean a huge price saving for all parties concerned. It also managed the risk of defects well with only single parts being scrapped rather than whole batches.

Seeing the principles displayed so effectively with Lego you would be foolish not to take a second look at your current processes. Even if you are not in manufacture there is still a lot to learn for this clear strategy for organising a business. For me it was a really interesting couple of days that I got a great deal from.