Did you know that the smallest batch in an Industrial Factory is one? One order. I remember back when Dell Computers first came out. They manufactured one order at a time. They do not have to maintain a large inventory of computers and associated parts and materials. They know that over-production is the number one source of waste.
The same is true with McDonalds… one order at a time… one order of a Big Mac, for example.
Both scenarios go through a similar flow: an order is pushed; the order is pulled to completion then released to the customer.
These are examples of a “one-piece-flow”… a batch of one.
The Kanban system can easily demonstrate this one-piece-flow. Wherein work is pulled when there is capacity. Limit the WIP per Kanban phase or state to one… this gets you the one-piece-flow.
Hyper-focused on that one piece getting done in the shortest sustainable Lead Time.
This embodies the phrase common to the Kanban community: ‘Stop starting, start finishing’.
According to Kublai Khan — as he and his army were in the process of conquering China: “There is no good of anything until it is finished!”
Let us look at this “batch size” from the other side of the spectrum: The Big Batch.
A less than optimum batch will decelerate flow. Big batch, by nature (as experienced in life (i.e., congested road) and at work), slows down flow.
Scrum is an example of a batch — in a small scale:
A bunch of highly prioritized stories (work) are bunched up — typically two weeks’ worth of work — during sprint planning into the team’s sprint backlog… queued up to be worked on for the next sprint. This is ‘Batch and Queue’ in action!
SAFe, like Scrum, is doing a similar thing that Scrum is doing… on a larger Fractal or scale!
SAFe’s batch size is larger than Scrum’s.
A bunch of highly prioritized stories (work) are bunched up — typically ten weeks’ worth of work — during PI planning.
This is ‘Batch and Queue’ in action… at a larger scale or Fractal!
A big batch also affects wait time and queue length. That is for the next Blog item: Accelerate Flow — Reduce Queue Length.