the board, the limit on work in progress, and the four metrics that measure flow
Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.
Three sizes in one archive — from a sheet on the fridge to a poster on the wall.
Definitions and practices are quoted verbatim from the Kanban Guide v2025.5 (kanbanguides.org). The flow relation is Little, Operations Research 9(3):383–387, 1961.
Work in progress equals throughput multiplied by cycle time. That is not advice or experience but a relation between queues, proved by Little in 1961, and it holds in any system where as much leaves as enters.
The consequence for a board is counter-intuitive. Throughput is how much the team gets done; starting more items does not make it larger. Cycle time, however, rises with work in progress directly: start twice as many and every single item waits twice as long.
That is why the number above the column is the only handle in the system that genuinely turns. It speeds nothing up — it makes the queue visible and shorter.
Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 5 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.
ten tasks, the year of each, the system, the figure — and the human it was measured against
who published each standard, when, what it does to the sound, and how many bits per second it allows
two scales · 1000 and 1024 · why a drive looks smaller
main axis and cross axis · which property belongs to which