Measurement
You have the cycle times. Now what does the picture mean?
A histogram of how long things take has four things in it worth acting on, and the average is not one of them. What to look for, and what each shape is telling you.
Section
Metrics and maths
The measures that get quoted in meetings, what each one actually counts, and the arithmetic behind them.
Queueing
How long will this backlog take to clear? There is an equation for that
Little's Law is usually taught on a factory floor. It works just as well on a hiring pipeline, and it answers the question everybody is arguing about in one line.
Quality
A ten percent rework rate is not a ten percent problem
Ten percent of work coming back does not cost ten percent more. It costs the second pass, the capacity the second pass eats, and the queue that grows behind it.
Variation
The average was met and a quarter of the orders were late
Twenty orders, a mean of six days against a six day promise, and five of them over it. The number that would have told you is not the average, and it is not hard to compute.
Bottlenecks
The hour you lost at the bottleneck did not cost forty five dollars
The station costs forty five dollars an hour to run and two thousand nine hundred to stand still. Multiplying by the wrong one is how bottleneck projects get refused.
Utilization
The last ten percent of utilization costs more than the first eighty
A desk at eighty percent utilization takes five times its own handling time to answer. At ninety it takes ten. The step between them is one extra request an hour.
Queueing
Little's Law does not care what the board says
One claims desk, two honest answers to how long a claim takes. The difference between them is the queue, and the arithmetic that finds it fits on a single line.
Measurement
Cycle time and lead time are not the same number
A purchase order takes fifty five minutes of work and ten days to arrive. Both figures are right, and the gap between them is the only part worth managing.