Subway is the 2nd biggest fast food chain in the world and although my personal guiltier pleasure is Maccy D’s, I do indulge with a Subway a little more often. Partly, because I think it's a bit healthier and partly because I like watching the live production line!
“One Piece Flow” is the fabled “Lean” ideal for manufacturing with batch sizes of 1. Ideal for the fastest throughput time, minimum Work-In-Progress inventory, shortest customer wait times and Subway have mastered it.
When you go to Subway, it is exactly that speed and customisation that you are paying a premium for.
I found this video of a Subway worker making 16 identical sandwiches. Most conveniently, no other customers in the shop were waiting for their sandwich… So, did he make them all 1 at a time, like they do almost universally, not this time…. He made a big “BATCH” - grouping up the order to do them all at the same time.
15 minutes to make 16 Subs = less than 1 min / sandwich (normally it would be about 2-3 mins for a single sandwich). So clearly the productive output was much higher.
And here lies the eternal trade-off, big batches = higher output BUT longer customer wait times and all those other consequences mentioned earlier too. If you were the next customer in line, you’d be mighty pissed if you were waiting behind that order, and then another order of 16 tuna sandwiches because the server had discovered how “efficient” it is to save up all the tuna orders until he had enough order to start making a big efficient batch, then you have to wait for the vegetarian batch and and then your order got put in a queue waiting for just another 10 people to order the same so they could finally start your efficient batch…
It might be twice as efficient in terms of labour output, but it would put Subway out of business globally in a week! Matching your operations strategy to your system design is a big choice for operations managers.
To learn more on this giant topic, check out my YouTube video on Batch Sizes vs One Piece Flow a part of our online course “Lean Manufacturing A-Z: Operations Management & Six Sigma”
If you're ready to dive deeper into these concepts and gain continuous, in-depth learning on operations management, consider joining our Operations Management Academy!
As a member, you'll get access to four ops courses including our flagship course "Advanced Operations Management". Start your journey today and take the operations in your career and business to the next level!
Crack On!
Laurence Gartside
Rowtons Training
Responses