Single Piece Flow
Consequences: Single Piece Flow, when applied in the right situation, can result in a faster time to market, an earlier return on investment, reduced inventory costs, and rapid feedback cycles. However, it can also lead to waste if developers are allowed to get in each others way.
Applicability: Single Piece Flow should be considered in situations where the value stream needs to be optimized as far as possible. Note that for Single Piece Flow to be viable, it must be possible for multiple developers to work on one item simultaneously and without causing each other impediment.
Structure: A development team accepts and actions only one backlog item at a time. The Work In Progress is limited to one.
Intent: Minimize stock-on-hand to one item so as to deliver value more quickly and reduce waste
It’s best to do one thing at a time
Also Known As:
One Piece Flow
Motivation: In theory, the most efficient way to work is one item at a time. This minimizes the costs associated with maintaining inventory (stock on hand) and also brings value to market more quickly, thereby allowing a return on investment to be leveraged sooner.
Implementation: Single piece flow can be implemented for Lean Kanban teams of small size, where developers will not cause each other impediment by working on the same item. It is rarely implemented in Scrum development teams, since they are expected to formulate their own plan for the delivery of a Sprint Backlog, the release of value being deferred until the end of a Sprint and not before.
An Alternative to Kanban: One-Piece Continuous Flow, by Jim Coplien
In Search of One Piece Flow, by Corey Ladas