Pancyprian Product Dev III cheat sheet

Stage-gate model: Discovery → Scoping → Business Case → Development → Testing & Validation → Launch, with gates that require deliverables and go/kill/hold/recycle decisions.

Concurrent engineering overlaps phases to cut time-to-market; risk is higher rework if requirements freeze late.

Product lifecycle phases: Introduction, Growth, Maturity, Decline; marketing mix and pricing strategy (skimming vs penetration) change per phase.

Design freeze locks form, fit, and function; changes after freeze require engineering change orders (ECOs) with impact assessment on cost, schedule, and compliance.

NPD success metrics: time-to-market, development cost, product cost, quality (defects/recalls), and revenue from new products (e.g., % of sales from products < 3 years old).

Fuzzy front end (FFE) ends when the product concept is approved and a formal development project is chartered.

Platform vs derivative development: platforms share architecture across product families; derivatives reuse modules to lower cost and risk.

Spiral and agile hardware hybrids use iterative builds; each loop ends with a design review and updated risk register.

Five modes (Stanford d.school): Empathize, Define, Ideate, Prototype, Test; they are iterative, not strictly linear.

Define mode output is a point-of-view (POV) statement: [User] needs [need] because [insight].

Ideation rules: defer judgment, encourage wild ideas, build on others, one conversation at a time, stay on topic.

Divergent thinking generates options; convergent thinking selects using explicit criteria (desirability, feasibility, viability).

Prototype fidelity matches the question: low-fidelity for concept exploration, high-fidelity for usability and technical validation.

Test mode captures user feedback to refine POV and prototypes; a failed prototype is data, not failure.

Double Diamond (UK Design Council): Discover → Define (problem space), Develop → Deliver (solution space).

Design thinking complements analytical methods; it reduces uncertainty about user needs before large capital commitments.

Qualitative methods (interviews, contextual inquiry, diary studies) answer why; quantitative methods (surveys, analytics, A/B tests) answer how many/how much.

Sample size rule of thumb: 5–8 users per homogeneous segment uncover most usability problems in formative testing.

Requirements types: functional (what it does), non-functional (performance, safety, reliability), constraints (regulatory, budget, schedule).

MoSCoW prioritization: Must have, Should have, Could have, Won't have (this time).

Kano model: Must-be (basic), Performance (linear), Attractive (delighters), Indifferent, Reverse; classify via paired functional/dysfunctional questions.

Voice of Customer (VOC) to CTQs (Critical to Quality) via QFD House of Quality; roof shows trade-offs between engineering characteristics.

User story format: As a [role], I want [goal] so that [benefit]; acceptance criteria define done.

Traceability matrix links each requirement to design element, test case, and verification method (test, inspection, analysis, demonstration).

Concept generation methods: brainstorming, brainwriting (6-3-5), SCAMPER, TRIZ, morphological analysis, analogical transfer, and lead-user method.

SCAMPER prompts: Substitute, Combine, Adapt, Modify/Magnify, Put to other use, Eliminate, Reverse/Rearrange.

Morphological chart decomposes the problem into functions and lists means for each; combinations become concept variants.

TRIZ resolves contradictions using 40 inventive principles and the contradiction matrix; ideal final result (IFR) guides problem framing.

Pugh concept selection: datum concept vs alternatives scored +/–/0 against criteria; the winner becomes the new datum in later rounds.

Weighted decision matrix: score each concept per criterion (e.g., 1–5), multiply by weight, sum; sensitivity check on weights.

Functional decomposition breaks the overall function into sub-functions; each sub-function can be solved independently before recombination.

Concept screening should include manufacturing, cost, and IP/regulatory feasibility, not only performance.

Prototype taxonomy: physical vs analytical (simulation), comprehensive vs focused, low vs high fidelity.

Rapid prototyping: FDM (fused deposition modeling), SLA (stereolithography), SLS (selective laser sintering), and CNC machining for functional prototypes.

Design of Experiments (DOE): full factorial tests all combinations; fractional factorial screens many factors with fewer runs; response surface optimizes.

Taguchi methods use orthogonal arrays and signal-to-noise ratio to make designs robust to noise factors.

Usability testing metrics: task success rate, time on task, error rate, and satisfaction (e.g., SUS score; average SUS ≈ 68).

Iterative testing loop: build → test → analyze → revise; each iteration should answer a specific risk-reduction question.

Accelerated life testing (ALT) applies elevated stress (temperature, voltage, vibration) to estimate life using acceleration models (e.g., Arrhenius for thermal).

Verification confirms the design meets specified requirements; validation confirms the product meets user needs in the intended use environment.

Material selection criteria: mechanical properties (strength, stiffness, toughness), density, thermal/electrical properties, corrosion, cost, and recyclability.

Ashby charts plot material properties (e.g., strength vs density) to identify candidates; performance index M = σ/ρ for a lightweight tie.

Manufacturing processes: injection molding (high volume, tooling cost), CNC (flexible, low volume), sheet metal (bending, stamping), casting, and additive manufacturing.

Design for Manufacturing and Assembly (DFMA): minimize part count, standardize fasteners, design for insertion from one direction, avoid separate fasteners.

Tolerance stack-up: worst-case sums tolerances; statistical (root-sum-square) assumes independent distributions and yields tighter assembly tolerances.

Technical feasibility assesses capability (can we make it?), capacity (can we scale?), cost (can we hit target cost?), and risk (what could fail?).

Prototype-to-production transition: design for injection molding requires draft angles (typically 1–3°), uniform wall thickness, and radii to avoid warpage.

Failure modes and effects analysis (FMEA): RPN = Severity × Occurrence × Detection; prioritize highest RPN for mitigation.

Circular economy strategies: reduce, reuse, repair, remanufacture, recycle; design for disassembly and material separation.

Life Cycle Assessment (LCA) phases per ISO 14040/14044: goal and scope, inventory analysis, impact assessment, interpretation.

Ecodesign requirements (EU): energy efficiency, material efficiency, recycled content, and durability; RoHS restricts hazardous substances; WEEE governs e-waste take-back.

CE marking indicates conformity with applicable EU directives/regulations; the manufacturer issues a Declaration of Conformity and maintains a technical file.

ISO 9001 quality management principles include customer focus, process approach, and continual improvement (Plan-Do-Check-Act).

Risk management per ISO 14971 (medical devices): identify hazards, estimate risk, evaluate, control, and monitor residual risk.

Safety hierarchy of controls: eliminate, substitute, engineering controls, administrative controls, PPE.

Quality tools: control charts (variable vs attribute), Pareto analysis (80/20), cause-and-effect (fishbone) diagram, and 8D problem solving.

Triple constraint: scope, time, cost; quality sits at the center; changes to one affect the others.

Critical path method (CPM): longest path through the network determines project duration; float = late start − early start.

Earned Value Management: EV = % complete × BAC; CV = EV − AC; SV = EV − PV; CPI = EV/AC; SPI = EV/PV.

RACI matrix assigns Responsible, Accountable, Consulted, Informed for each task; only one accountable per task.

Tuckman team stages: Forming, Storming, Norming, Performing, Adjourning.

Risk register records risk, probability, impact, score (P × I), owner, response (avoid, mitigate, transfer, accept).

Communication plan defines stakeholders, information, frequency, format, and channel; a RAID log tracks Risks, Assumptions, Issues, Dependencies.

Agile ceremonies: sprint planning, daily stand-up, sprint review, retrospective; roles: product owner, scrum master, development team.