I. Organizing the Review
How to organize the review. Based on industry standards, the review process is structured as follows: Review Team—composed of cross-disciplinary technical personnel (joint review by mechanical, electrical, process, and procurement teams) to ensure alignment with the existing production line and the enterprise’s capacity planning;
Agenda—Team leader clarifies review rules and scoring criteria → Project manager presents core proposal details (15 mins) → Review team asks questions focusing on technical challenges, risks, and optimization opportunities (30 mins) → Item-by-item scoring (100-point scale) → Group discussion to reach a consensus; Stages—reviews are conducted at specific milestones: after conceptual design, after detailed design, and prior to prototype fabrication; Review Package—3D models, drawings, requirement lists, calculations, simulation or test results, risk logs, supplier feedback, standards, and checklists are distributed to reviewers in advance; Minutes—meeting minutes distributed within 24 hours, with action items assigned specific owners and deadlines—the review is not a mere formality; a review without closed-loop action items is effectively a wasted effort.
II.
Feasibility Assessment
How to assess feasibility.
According to industry review standards, proposal feasibility is evaluated via the following: the “Three Checks”—technical feasibility (e.g., algorithm accuracy, structural implementability), cost reasonableness (budget deviation ≤10%), and cycle time matching (demand deviation ≤15%); equipment assessment—feasibility, cost, production efficiency, and structural feasibility of individual components; structural integration—functionality (capacity and precision), stability, safety, ergonomics (ease of operation), and aesthetics; efficiency—whether the machine’s design output meets customer requirements; simplicity—mechanisms should be simple to debug and maintain, with parts designed for easy machining; and operating conditions—evaluating cycle time, load, repeatability, continuous runtime, power configuration, noise, and protection ratings in the context of materials and the environment (performance in short-term no-load tests may differ from actual operating conditions; the core of the feasibility review is comparing the proposal against the requirements specification—any item that fails to match results in the proposal being returned).
III. The Four Design Attributes
How are the four design attributes reviewed?
In industry design reviews, the “four attributes” serve as criteria for a “one-vote veto”: functionality—ability to achieve the functions and precision metrics required by the customer;
manufacturability—avoiding unnecessary high-precision requirements or irregular shapes, clarifying manufacturing processes, and ensuring feasibility for the machine shop; assemblability—allocating sufficient space for assembly, establishing a logical assembly sequence, and avoiding conflicting assembly steps or repetitive disassembly; and maintainability—ensuring easy replacement of wear parts and clear access for maintenance. Structural analysis—comprehensive identification of load conditions (static, dynamic, fatigue, impact, thermal), structural safety factors of 1.25 to 2.0 (depending on application and material uncertainty), fatigue life calculation, identification of stress concentrations (notches, holes, sharp angles), buckling checks for slender/thin-walled components, and anti-loosening measures for bolted connections. Drawing review—machine assembly drawings and part drawings annotated according to national standards, selection of actuators and electrical control components, lists of machined parts and standard parts, and sequence-of-operation descriptions. Failure to meet any of these four core indicators results in rejection; the review of these four attributes acts as the first quality gate for custom equipment design.
IV. Safety and Tooling
How are safety and tooling reviewed?
According to industry safety standards, safety reviews are conducted as follows: Risk Assessment—following the six steps of ISO 12100: inherently safe design (eliminating or reducing risks, such as narrowing gaps to prevent finger access) → protective devices (fixed guards, interlocking movable guards, light curtains) → supplementary protective measures → information on residual risks → overall verification; Functional Safety—design measures, technical measures, organizational measures, and overall verification; Tooling and Fixture Review—product datum scheme (surfaces, holes, axes, center planes), positioning and clamping concepts (constraining degrees of freedom and reaction force paths), error budget (affecting error allocation and remaining design margin), MSA acceptance plan (parts, instruments, environment, acceptance criteria), and wear/maintenance limits (replaceable parts, inspection, limits for “as-new” condition); Release Gates—drawing review (contact sequence, interface scope), bench functionality (pressure pad sequence recording), machine installation trials (loaded gap test cuts, CTQ recording), and recovery (fault check, reset, role handover, documentation)—safety review establishes the baseline, while tooling review ensures precision;
the solution is complete only when both have passed.
V. Targets and Costs
How are targets and costs reviewed?
Based on industry acceptance practices, here is how to evaluate cost-related metrics: **Quantify acceptance criteria**—specify exact numerical values, testing methods, and tools for core metrics such as cycle time, yield rate, equipment utilization, critical dimension accuracy, and failure rate; avoid vague language (e.g., if raising yield from 85% to 98%, require data from similar scenarios and sign an agreement stipulating compensation for failure to meet targets). **Verify spatial requirements**—conduct on-site spatial assessments covering equipment dimensions, operator interface positioning, maintenance access (door swing direction), material flow paths, temporary repair clearance, and safety fencing boundaries; many projects that appear to fit on paper run into real-world bottlenecks involving electrical cabinet door clearance, manual loading access, forklift turning radii, and fixture replacement. **Analyze costs**—calculate Total Cost of Ownership (TCO) by accounting for equipment depreciation, energy consumption, consumables, spare parts, scheduled maintenance, labor, and losses due to downtime; compare the comprehensive cost per qualified unit over a 3-to-5-year horizon (e.g., a machine costing 10% more upfront may prove more economical over three years due to stability and savings on labor and maintenance)—only by fixing specific numerical targets and calculating TCO can the review truly address the critical issues.
Conclusion
How should a custom non-standard assembly line proposal be evaluated?
The conclusion is to systematically pass through five key checkpoints: organization, feasibility, the “four attributes” (functionality, reliability, maintainability, and safety), safety compliance, and performance metrics.
Organization: Cross-functional review team; 15-minute presentation followed by 30 minutes of Q&A; item-by-item scoring on a 100-point scale; and closure of action items from meeting minutes within 24 hours. Feasibility: Technical feasibility; cost variance ≤10%; cycle time variance ≤15%; structural design ensuring functionality, stability, safety, and ergonomics; and a mechanism that is simple, easy to debug, and easy to maintain. The “Four Attributes” (functionality, manufacturability, assemblability, and maintainability) are subject to a “one-vote veto” rule; full identification of load conditions; safety factor of 1.25 to 2.0; and verification of fatigue, stress, and buckling. Safety & Tooling: ISO 12100 risk assessment (inherent safety design → safeguarding → residual risk → verification); error budgeting for datum, positioning, and clamping; MSA acceptance plan; and wear limits. Target Costs & Metrics: Fixed values and testing methods for cycle time, yield, utilization rate, and failure rate; TCO calculation over a 3–5 year horizon;
and on-site spatial verification (door opening direction, material flow paths, and maintenance clearance).
Per industry convention, the value of a design review lies in identifying flaws rather than merely going through the motions—a design is considered to have truly withstood the test only if at least three substantive issues are identified in each review round.
