Requirement List
A requirement list is a numbered breakdown of needs in which every line expresses a single verifiable expectation. It is written in the form "the system shall do X" or "the system shall not do Y"; each item is given a number and that number is tracked all the way to the test record, the board and the software version.
A specification is read in narrative form, whereas a requirement list exists to be tracked. If two expectations are written together in one item ("it shall drive the relay and light the fault LED"), when one is met and the other is not, the status of the item stays ambiguous; for this reason every line is a single idea.
- Numbering: a fixed identity such as G-012 is given, and the number is preserved even if the item text changes.
- Priority: items are separated as mandatory, expected and optional; when a budget or space constraint arises, it is clear which are cut first.
- Verification method: measurement, visual inspection or field test — it is written next to each item.
On a custom control board this list is typically a few dozen lines: number of inputs, output current, protection behaviour, adjustment ranges, interface and labelling. The production test fixture is also derived from this list — which item will be verified one by one on every board is marked here.
The context in which this term is used: Our Services