Product Development - NPTEL

🌟 Week 1: Foundations of Product Design

Introduction
Every successful organization must constantly innovate. Product design is the transformation of an idea into reality through specifications that satisfy customer needs while staying cost-effective and manufacturable. Poorly designed products often fail due to wrong timing, poor design, or overestimated markets.

Why New Product Design?

• Survival and long-term growth.

• Address unmet needs.

• Respond to competition.

• Recover declining profits.

• Overcome stagnation.

New Product Development (NPD) Process
Idea generation → Screening → Concept & Testing → Marketing Strategy → Business Analysis → Development → Test Marketing → Commercialization.
(Exam tip: quality, cost, development time, and capability = success metrics).

Product Life Cycle (PLC)

1. Introduction → low sales, high costs, negative profits.

2. Growth → rising sales and profits.

3. Maturity → peak sales/profits, intense competition.

4. Decline → sales/profits fall, replacements enter.

Product Policy & Selection

• Lowest price (e.g., carry bags).

• Highest quality (e.g., medical equipment).

• Cost–quality compromise (e.g., TVs, mobiles).

• Safety-first (e.g., implants, electrical gadgets).

Selection tool = SWOT analysis (Strengths, Weaknesses, Opportunities, Threats).

Good Product Design Features
Functionality, Reliability, Productivity, Quality, Standardization, Maintainability.

Assignment Highlight:

• 70–80% cost fixed at design stage.

• PLC Intro phase = negative profits.

• Standardization ensures interchangeability.

• Biodegradable implants demand quality + safety policy.

---

🌟 Week 2: Value Engineering (VE)

Definition
VE = organized, creative study of functions to maximize:

$$Value = \frac{Performance}{Cost}$$

It’s not cost cutting but value optimization.

Causes of Poor Value: poor coordination, outdated standards, wrong assumptions.
Advantage: better design, improved quality, cost reduction without loss of function.
Note: Design team has maximum cost-saving impact.

VE Job Plan (VEJP)
Orientation → Information → Functional Analysis → Creative → Evaluation → Development → Presentation → Implementation.

Function & Analysis

• Function = Verb + Noun (e.g., Conduct Current).

• Types: Primary vs Secondary.

• FAST (Function Analysis System Technique): Ask Why? to move higher, How? to move lower; links via AND/OR logic.

Case Study (Divan Furniture)

• Alternatives: reduce board thickness, change pipe gauge, add wheels, use waste material.

• Results: 14.61% and 19.60% cost reduction while retaining durability and appearance.

Assignment Highlight:

• VEJP correct order (Orientation → Information → Functional Analysis → Creative).

• FAST uses AND/OR logic.

• Evaluation criteria: rigidity, weight, durability, appearance.

---

🌟 Week 3: Advanced Tools

Quality Function Deployment (QFD)
Structured method (Japan, 1972) to turn Voice of Customer → Technical Specs.
Core tool = House of Quality (matrix with roof).

Phases: Product Planning → Product Design → Process Planning → Production Planning.
Benefits: faster development, fewer complaints, reduced changes, happier customers.

Computer Aided Design (CAD)

• Components: Computer graphics + Geometric modeling + Design tools (FEM/CFD).

• Uses: auto, aerospace, medical, defense, plastics.

• Key outputs: mass properties, FEA analysis, drafting, review.

Robust Design (Taguchi)
Goal = insensitivity to noise factors (external, internal, unit-to-unit).
Stages = System Design → Parameter Design → Tolerance Design.
Example: Optimize paint gloss vs humidity/temp variation.

Design for Excellence (DFX)
Design for X (Manufacturing, Assembly, Cost, Reliability, Safety).

• DFM → reduce manufacturing complexity & cost.

• DFA → reduce assembly effort and part count.

Ergonomics
Optimize human factors:

• Physical (posture, strain).

• Cognitive (mental load, decisions).

• Organizational (shifts, teamwork).
  Case: Office chair, crane cabin — adjustability, visibility, vibration reduction.

Assignment Highlight:

• QFD = House of Quality, not circular.

• Competitive assessment = how firm performs vs competitors.

• Sheet metal rule = edge–hole spacing ≥1.5–2× thickness.

• Cognitive ergonomics = mental processes.

---

🌟 Week 4: Practical Guidelines + Prototyping

DFMA

• DFA = assembly cost reduction (minimize operations, self-fastening).

• DFM = part production cost reduction (simplify features, standardize).

• Principles: minimize components, use modular design, avoid separate fasteners, use chamfers/self-alignments.

Manual Assembly

• Handling: symmetry, avoid jamming/tangling/slippery/hazardous parts.

• Insertion & fastening: chamfers, air relief, secure quickly, locate before release.

Process Guidelines

• Casting: fillets 3–25 mm, uniform cross-sections, use chills, avoid sharp corners.

• Machining: avoid partial holes (≥75% area inside), L/D ≤ 8, rounded keyways.

• Injection Molding: draft ≥0.5°, uniform wall thickness, ribs = 0.5× wall, PS walls 0.035–0.150 in.

• Welding: gas purity, preheat, post-weld heat treatment.

Rapid Prototyping (RP)
5 steps: CAD → STL → Slice → Build → Clean/finish.
Advantages: fast, accurate, less waste, no tooling, early error detection.

Processes:

• SLA: UV-cured polymer, smooth finish.

• SLS: laser sintered powders, functional parts.

• LOM: laminated sheets, low-cost.

• FDM: extruded filament, widely used.

Assignment Highlight:

• Injection molding draft = ≥0.5°.

• Machining partial holes = ≥75% area inside material.

• Turning L/D ≤ 8.

• Casting fillets = 3–25 mm.

• RP steps = CAD → STL → Slice → Build → Finish.

---

✅ Final Quick Exam Checklist

• 8 NPD steps in order.

• PLC phases & profit signs (Intro = negative).

• Value = Performance / Cost (not cost cutting).

• VEJP order + FAST why/how logic.

• QFD House of Quality blocks (Customer, Relationship, Correlation, Assessment, Targets).

• CAD stack + FEA in engineering analysis.

• Robust design = System, Parameter, Tolerance.

• DFMA differences + DFA rules (min parts, self-align, gravity insertion).

• Manual assembly rules (symmetry, chamfers, locate before release).

• Casting fillet 3–25 mm, chills; Machining L/D ≤ 8; Injection molding draft ≥0.5°, uniform walls; RP 5 steps + SLA/SLS/LOM/FDM.