Targets and thresholds · The variation band · Element
The signal rule
What counts as a real change.
The part
What it is
A single reading outside the band, or several consecutive readings on one side of the centre. Both are standard and both are better than reacting to any movement.
The rule should be written down, or it will be applied differently depending on whether the movement is favourable.
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.
Applied symmetrically
Whether favourable and unfavourable movements are treated alike.
Choice shared type
The other elements in the variation band
The band
The range within which movement is not news.
LearnThe false alarms
How often the organisation reacted to noise.
Learn