The main difference isn't how long it takes to do a set number of boxes. It's the reduction of work in process, as well as the speed of a single finished good through the system.
Interesting video. I have always assumed that if you only have one worker it doesn’t matter if you do single piece or batch. I really like this demonstration showing that, in this case, SP is faster. After a serious analysis (which I haven’t done) I think we would find that there is a bunch of the 8 Wastes added into the batch processing that are eliminated in the single piece processing. Thanks for this video.
Awesome! I noticed in the Batch side, you actually were doing some one piece flow work. When bagging the PCB, you put it right into the box, where it would normally have been bag each PCB, then place each bag in the box, then close each box. But it really drives thing home how must faster one piece flow is vs batch.
This is a fake example, because the task isn't a realistic manufacturing task. Having run one-person production lines with runs in the hundreds of real world units, I can assure you that batch processing is much faster per unit on actual manufacturing units. In real production environments, each step you do requires assembling tooling, configuring the space, locating inventory, and many other potential tasks. Batch production allows these unavoidable muda events to be distributed over tens or hundreds of units, not added to every unit. One-piece flow will give you a lower first unit time, but batch will win every time in a single worker thoughput test involving real manufacturing. That's why we talk about economies of scale.
This is not definitive proof for various reasons. Right off of the bat the 1PF operator is operating 2 seconds faster than the batch operator. This is not how you conduct controlled experiments. The second problem is the batch operator has no standards in which they place the box. Batch manufacturing =/= lack of organization. Another issue I'm having with is why aren't the materials properly staged to deduct reaching space for the batch operator? The stickers themselves should be place directly close to the unassembled boxes then placed on the unassembled boxes. Each time it's placed you flip to cardboard in a stack. It would have been a much faster process. The same goes for the stickers for the cards as well, just like the unassembled boxes you could stage the cards with the stick. The only difference being as you stage you slide the others behind. Same deal with the bags: I would have staged the bagged cards and would have been able to pick up multiple bags thus reducing reach time. You could utilize the table via three sections. Yes, it takes a little more space during assembly but you weren't using that space anyway. I've done kitting for years and in practice batching was always faster.
The primary conclusion from this experiment is that the batch process is not optimized, e.g. too little storage and process space. Done consistently and with many samples, the throughput should be the same. You could even argue that the batch process should be faster. The primary benefit of single item processing is the reduced WIP and cycle time.
