Example Requirement Specification
Project: HealthTrack Mobile App — Medication Reminders Module
Prepared by: Gilb International AS
Methodology: Tom & Kai Gilb's Planguage requirements and value-engineering methodology
Status: Illustrative sample — not a real client deliverable
How to read this specification
Every requirement in a Gilb International specification is expressed using the Planguage format. Each requirement states:
- —Type: the kind of thing being specified (Function, Performance, Usability, etc.)
- —Scale: the unit of measurement — what exactly we are measuring
- —Meter: how we measure it — the test procedure
- —Tolerable: the worst acceptable value (the floor)
- —Goal: the target value the delivered system should achieve
This makes every requirement testable. There is no ambiguity about whether a requirement is met.
Requirement 1 — Medication Reminder Delivery Rate
Type: Reliability · Gist: The system must reliably deliver medication reminders at the scheduled time.
| Scale | Percentage of scheduled medication reminders delivered to the user's device within 60 seconds of the scheduled time, measured over a rolling 7-day period per active user. |
| Meter | Automated test: a test account with 4 daily reminders runs for 7 days on each supported platform (iOS 16+, Android 12+). Count delivered-on-time / total scheduled × 100. |
| Tolerable | 95% |
| Goal | 99.5% |
A reminder is "delivered on time" if the push notification appears within 60 seconds. Silent failures and late notifications both count as failures.
Requirement 2 — Reminder Setup Time
Type: Usability · Gist: A new user must be able to set up a medication reminder without assistance.
| Scale | Time from entering the "Add Medication" screen to confirmation that the first reminder is scheduled, measured in seconds. |
| Meter | Moderated usability test with 10 participants (adults 45–75, moderate smartphone familiarity). Record task completion time. Report median and 90th percentile. |
| Tolerable | Median ≤ 120 s; 90th percentile ≤ 240 s |
| Goal | Median ≤ 60 s; 90th percentile ≤ 120 s |
Participants must not have seen the app before. No verbal guidance is given during the task.
Requirement 3 — Missed Dose Follow-up
Type: Function · Gist: When a reminder is unacknowledged for 30 minutes, trigger a follow-up prompt.
| Scale | Whether a follow-up prompt is triggered when a reminder remains unacknowledged for 30 minutes (Boolean: triggered / not triggered). |
| Meter | Automated test: schedule a reminder, do not interact, wait 31 minutes. Verify that a second notification appears in the device tray. |
| Tolerable | 100% — zero tolerance (safety-relevant failure) |
| Goal | Same as Tolerable |
Requirement 4 — Specification Legibility
Type: Usability (specification quality) · Gist: Every requirement must be independently understandable by a developer without clarification.
| Scale | Proportion of requirements rated "clear — I can implement this without asking a question" by a developer unfamiliar with the project, on first reading. |
| Meter | Three developers from outside the project team each read the specification independently. For each requirement they rate: clear / needs one clarification / unclear. Report percentage rated "clear". |
| Tolerable | 90% rated "clear" |
| Goal | 98% rated "clear" |
What this looks like in practice
Each of the requirements above is:
- ✓Quantified — expressed with a number and a unit, not a vague adjective
- ✓Measurable — the Scale and Meter together define a repeatable test anyone can run
- ✓Testable — you can determine pass/fail against Tolerable and Goal without interpretation
This is what Gilb International delivers. The methodology scales from a handful of requirements for a focused feature to hundreds of requirements across a complex enterprise system.
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