Worked example: a mobile inspection robot brief

1. State the task in plain language

The proposed task is to collect images of agreed inspection points along a depot route. A person reviews the images and decides whether a closer inspection is needed. The initial assessment concerns image usefulness and operator workload. It does not include autonomous defect decisions, equipment maintenance or replacing mandatory inspections.

• User: a trained depot inspection operator.
• Decision: whether the approach merits a controlled prototype trial.

2. List the site assumptions to confirm

Assume the first assessment uses a segregated area with a level hard surface and a supervisor present. These are planning assumptions, not verified site conditions. Before selecting a platform, measure the route, inspect thresholds and confirm lighting, access and recovery arrangements. Record any condition that falls outside the initial scope.

• Questions: narrowest opening, turning space and surface changes?
• Exclusions: stairs, public access and operation alongside moving depot traffic.

3. Define the camera's job and interfaces

The camera must provide images that the nominated reviewer can use for the agreed inspection task. The brief should identify viewing positions, lighting and the features to distinguish. Record the camera, mount and cable mass together, then establish supply requirements, data connection, recording format and access for cleaning or adjustment.

• Evidence question: can the reviewer distinguish the agreed reference features?
• Open question: stationary capture or capture while moving?

4. Describe the operator's control

For this example, one operator supervises movement and the supervisor controls access to the trial area. The system must make its active state understandable. The engineering review should define stopping, interrupted communications and recovery behaviour. An ArduPilot-based option would require its applicable pre-arm checks to be reviewed as part of setup.

• Questions: how does the operator confirm the selected vehicle and current state?
• Record the stop instruction and who authorises a restart.

Reference: ArduPilot Rover: Pre-Arm Safety Checks

5. Connect requirements to evidence

Give each requirement a check and an owner. For example, route access can be assessed against measured clearances; image usefulness needs representative images reviewed by the intended user. NASA's guidance distinguishes requirement verification from validation for the user's intended task. Both questions matter here, and the evidence should say which one it answers.

• Access: record the measured configuration and route constraints.
• Images: record camera settings, conditions and the reviewer's result.

Reference: NASA Systems Engineering Handbook: Product Realization

6. Record the controlled trial

Use a short run sheet identifying configuration, route, conditions and planned checks. Capture setup time, operator interventions and missing images alongside successful captures. Do not infer battery endurance from a short route demonstration. An unexpected fault or incomplete record should remain visible in the assessment, with a decision about further work.

• Retain original images and logs with the run identifier.
• Separate measured results, observations and unresolved questions.

7. End with a bounded decision

The review should decide whether the evidence supports another development stage and identify what must change first. Useful outputs include an updated brief, interface questions, representative images and a list of operating limits. Success in this segregated assessment would not establish suitability for unsupervised operation or a busy working depot.

• Next decision: proceed, revise the approach or stop.
• Name owners for missing evidence and the next review.

Further reading

• ArduPilot Rover: Pre-Arm Safety Checks
• NASA Systems Engineering Handbook: Product Realization