Chapter 30 — Verification laboratory I

Chapter 30 — Verification laboratory I

Lesson map

Lesson 30 published. Map, example, EX088.

flowchart TD
  N0["Learning outcomes"]
  N1["30.1 Requirements verification"]
  N2["30.2 Usability verification"]
  N3["Lab — Requirement verification results"]
  N4["30.3 Recording evidence"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5
  N5 --> EX["Worked example"]
  EX --> Q["Exercise EX088"]

Logical drawing

flowchart LR
  N0["Learning outcomes"]
  N1["30.1 Requirements verification"]
  N2["30.2 Usability verification"]
  N3["Lab — Requirement verification results"]
  N4["30.3 Recording evidence"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> Q["EX088"]

[Learning outcomes]
    |
    v
[30.1 Requirements verification]
    |
    v
[30.2 Usability verification]
    |
    v
[Lab — Requirement verification results]
    |
    v
[30.3 Recording evidence]
    |
    v
[Synthesis]
    |
    v
[Worked example] --> [Exercise EX088]

Learning outcomes

You will (1) verify the reporting service against requirements; (2) run usability verification with participants; (3) record evidence of verification.

30.1 Requirements verification

In the verification laboratory, Aiko checks each requirement from chapter 21. She sends synthetic test emails and reports them from desktop and mobile, timing thank-you messages. She checks that the dashboard shows only groups of twenty or more and that no individual export exists. She confirms operator training modules take under five minutes. Each check produces a pass or fail with evidence such as timestamps or screenshots. Verification turns requirements into proof rather than assumption. Tests are run twice on different days to rule out chance timing effects, and any result close to a threshold is repeated.

30.2 Usability verification

Aiko recruits eight staff volunteers to complete tasks: report an email on a phone, find the verdict message and find guidance on what to report. She measures success and time without helping. Seven succeed on all tasks; one cannot find the guidance because it is linked only from the intranet. She adds a link to the thank-you message. Usability verification checks that requirements were met in a way real people can use, which technical checks alone cannot confirm. She also records where volunteers hesitated, even when they succeeded.

Lab — Requirement verification results

# Requirement verification results, before and after fixing a notification setting (synthetic).
reqs = ["one-tap mobile report", "thank-you within 1 minute (desktop)", "thank-you within 1 minute (mobile)",
        "dashboard groups >= 20 only", "no individual export", "operator module <= 5 minutes"]
round1 = [True, True, False, True, True, True]
for r, ok in zip(reqs, round1): print(f"{'PASS' if ok else 'FAIL'} {r}")
print(f"round 1: {sum(round1)}/{len(reqs)}; round 2 after notification fix: {len(reqs)}/{len(reqs)}")

Run with python3 lab_verify.py. Verified output:

PASS one-tap mobile report
PASS thank-you within 1 minute (desktop)
FAIL thank-you within 1 minute (mobile)
PASS dashboard groups >= 20 only
PASS no individual export
PASS operator module <= 5 minutes
round 1: 5/6; round 2 after notification fix: 6/6

30.3 Recording evidence

Aiko records results in a verification table linking each requirement to its test, date, result and evidence. One requirement fails at first: mobile thank-you messages take three minutes on one phone model because of a notification setting. The IT team changes the setting and the retest passes. The table becomes evidence for the regulator and a baseline for re-verification after future changes. Prof. Kerr notes that recorded failures make verification more credible. The table is stored with the requirements document and version controlled, so that each future release can be verified against the same tests and any change in results can be traced.

Worked example

Aiko verifies requirements with timed tests, verifies usability with eight volunteers, fixes a guidance link and a notification delay, and records evidence.

Synthetic case. Tests and results are synthetic.

Errors and limits

Volunteers may be more confident than typical staff. Phone models vary widely.

Exercises

• EX088 — Dashboard check. What did Aiko verify about the dashboard? Rubric: 3 = only groups of twenty or more and no individual export;; 2 = aggregation;; 1 = vague;; 0 = none.
• EX089 — Usability fix. What usability problem did one volunteer reveal? Rubric: 3 = guidance linked only from the intranet;; 2 = link;; 1 = vague;; 0 = none.
• EX090 — Lab verification. How many requirements passed in each verification round? Rubric: 3 = 5 of 6 passed, then 6 of 6 after the notification fix;; 2 = 5 then 6;; 1 = vague;; 0 = none.

Synthesis

Verification proves requirements are met technically and usably, with recorded evidence including failures.

Continue studying — chapter 30 of 50

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