How these notes are written

Structure

Most notes follow the same shape: what the measure is, why it is harder than it looks, the method, where the method misleads, and how to tell whether it worked.

The sections on what does not work are not optional. A description of throughput measurement that omits the counting-point problem describes a number that will disagree with someone else's.

Aggregate by default

A principle running through the whole collection: almost every operational question is answerable without attributing anything to a named person.

Where individual data is genuinely required — safety investigation, equipment licensing, support, pay — the notes say so, and describe the controls each case needs.

The uncomfortable material

Output per person attributes system performance to individuals, and the difference is usually the layout.

Rate pressure increases injury risk, through a mechanism that is well established and slow to become visible.

Monitoring read as adversarial degrades the data it collects, because scan discipline and exception reporting both depend on cooperation.

Detection is close to the weakest control in the safety hierarchy, and it is routinely substituted for the physical separation that should have been installed.

These are stated because a programme that does not know them reports success while nothing improves.

Legal material

Descriptions of safety duties, data protection obligations, consultation requirements and working time rules are general and jurisdiction-dependent. They are not legal advice and the notes say so.

Commercial position

No vendor material. No sponsored content. No affiliate links. No product rankings.