The flow efficiency

Processing time as a share of elapsed time, for the process as a whole.

The part

What it is

A single number that reframes the whole conversation. Values in the low single digits are common and are not a sign of a badly run organisation.

It is most useful as a before-and-after measure, because the absolute figure invites arguments about definition.

The smallest level

The attributes it carries

Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.

Flow efficiency
Processing time over elapsed time — usually far lower than expected.
Percentage shared type
Total lead time
The elapsed time end to end, which is what the customer experiences.
Duration shared type
Constraint
Which step sets the pace, since improving anything else moves the queue rather than the total.
Reference shared type