ValiStera Academy — Module 2 / Lesson 2.4
Write testable user requirements

This lesson has required companion reading below, including material not spoken in the video. Complete it before the assessment.


From adjective to requirement
A user requirement should communicate an actual need. The phrase easy to clean is useful as a concern but too vague to verify on its own. Ask what product residues are expected, which surfaces must be accessible, what cleaning process is intended and how the design will support it. Do not insert a universal surface finish or residue limit simply because another project used it. The scientific basis belongs to the actual application.

One requirement, one trace
For our fictional example, requirement URS-01 states that product-contact materials must be identified and supported by approved compatibility evidence for the defined product and cleaning agents. The design review checks the proposed materials. Later verification checks the installed materials and supporting records. The requirement has an identifier, a clear subject and an evidence path. The site defines the actual acceptance criteria and document controls.

An illustrative measurable need
Consider a training-only temperature indication requirement: within the selected operating range, indication error must remain within a project-defined tolerance when compared with a suitable calibrated reference. The range and tolerance are not supplied here because the process basis is still missing. This is a deliberate unresolved requirement, not a pass. The exercise asks you to identify the information needed to finalize it before procurement or testing.

Control revisions
Requirements evolve as knowledge improves, but uncontrolled changes break traceability. If the intended batch range changes, assess effects on mixing, measurement, cleaning and verification. Retain the reason for the revision and the approval trail. Do not silently edit a requirement after a failed test to make the result pass. In the activity, rewrite three vague statements and clearly mark any assumptions that require resolution.