One Piece Flow , The Enevelope Stuffing Vignette

I was recently riding home with a professional colleague who was (very creatively in my opinion) writing New Years cards for loved ones based on the Chinese calendar. We happened to be talking a little bit about LEAN at the time, and I remarked that she was using a mass production process to put the cards together. I mentioned the example given in LEAN Thinking, that it would take less time to prepare the cards using one piece flow. I couldn’t exactly quantify the difference, though, and she raised some excellent points about her need to have a mobile factory as we hopped up and down the east coast.

Thanks for Ron Pereira from LSS Academy for putting together a video that shows this. Even if you don’t have a postal carrier standing by to deliver each envelope, it takes less time to do your part as one piece flow.

This is a very accessible example that can be used to talk about Toyota Production methods in health care. How many other processes do you engage in that involve batching work?


Very helpful in demonstrating the concept. We will use this demonstration in our work to streamline triage processes in my emergency department.

Excellent example and my imagination lets me insert patient care situations to see the value. Thanks

Linda and Ruth, I am glad such a simple demo is both available and useful. It seemed a bit counter-intuitive until I watched it myself.

Enjoy and keep me posted on how you transform using LEAN,


The video is very straightforward and a helpful demonstration. Clearly you weren't working harder or faster in the one-piece-flow. So where is the difference in time come from? You cut the time by between 1/4 and 1/3, a substantial reduction. The time savings comes from reduced handling – all the times you picked up the envelope and put it aside in the first batch situation was additional / wasted time.

The same is true with healthcare. Think of all the times the patient is "picked up" – attended to, and "put aside" – waiting for transport, waiting for test results, waiting for a doctor…not to mention the wasted time and motion to move from department to department.

I consult in Lean, primarily in manufacturing, so I am always looking for good examples. Thanks for sharing.

Hello all, interesting topic (s). When one thinks about mass production on a large scale… think about the production layout, if they were machines one might have a bank of certain machines in an area producing several hundred parts.. when they were finished.. they would be transported to another area… for the second process.. then moved again to the next and so on..if one were to do a simulation to the envelopes in that same manner.. having one person sitting at one table, complete the ten pieces and get up to move the "parts" to someone seated at another table for the second process (stuffing) then to the third at another location and so on.. then after completing all the processes. Re-organize the production layout (machines) but in this case have the people sitting next to one another it so that those same people are in a process that is conducive to a one piece flow, seriously think about how much time you would be saving???? Which is how I have seen many a companies have their processes set up. Makes a professional like me look like a hero… I like simulations

Ted Eytan, MD