Lesson 74 of 78 · Define the System
Requirements, Architecture Options & Concept Review
Turn the brief into a verification cross-reference matrix:
| ID | Requirement | Rationale/source | Verification | Acceptance |
|---|---|---|---|---|
| PERF-01 | ≥30 good units/h for mix A | baseline + demand | timed run | 95% lower confidence bound meets target |
| QUAL-02 | detect defined defect set | quality study | blinded test set | sensitivity/specificity thresholds |
| MAIN-03 | routine change item accessible | maintenance review | demonstration | trained person completes safely within limit |
Include mechanical, electrical, control, data, safety, human, operational, maintenance, cybersecurity, environmental, and decommissioning requirements.
Generate architectures
Develop at least three: simple fixture/assist, dedicated mechanism, and flexible mechatronic or robotic system. Sketch functional blocks, material flow, information flow, energy, people, service, safety boundary, and responsibility.
Use calculations only precise enough for the decision: payload/reach, torque, cycle budget, sensor feasibility, footprint, throughput, energy, safety concept, and cost range. The goal is to retire fatal flaws before detailed CAD.
Review with evidence
Present requirement coverage, decision matrix, sensitivity, top risks, unknowns, experiments, lifecycle cost range, worker feedback, and reasons alternatives were rejected. Invite challenge at interfaces: part-to-fixture, sensor-to-controller, controller-to-drive, robot-to-PLC, cell-to-operator, maintenance-to-energy control.
Gate 2
Pass only if the selected architecture covers critical requirements, no unresolved hazard makes the concept untenable, economics remains plausible under downside assumptions, and a feasible experiment exists for every high-risk unknown. NIST’s focus on performance requirements and test methods is the model: capability must be stated so another person can verify it 1.
Source trail
References
- 1Robotic Systems for Smart Manufacturing Program. National Institute of Standards and Technology. verifiedMeasurement science, performance metrics, test methods, interoperability, planning, agility, and collaborative workcell integration. Cited at: measurement science.
Further reading
- Design and Manufacturing I. MIT OpenCourseWare. verifiedProject-centered course on electromechanical design, machine elements, experiments, drawings, modeling, fabrication, and technical review.
- Design and Manufacturing II. MIT OpenCourseWare. verifiedModern manufacturing organized around process physics, equipment and control, manufacturing systems, and design for manufacture.
Check your understanding
- What links a requirement to eventual proof?
- A verification method and acceptance threshold
- A mood board
- A vendor promise only
- A broad adjective
Traceability connects the need, requirement, design feature, and objective evidence.
- What should a concept review expose?
- Assumptions tradeoffs interfaces hazards failure modes uncertainty and evidence gaps
- Only the chosen rendering
- Only price
- No rejected alternatives
Reviews are valuable when decisions can still change and the reasoning is visible.