Engineering Design Methodology

Design Process Overview

We follow a structured engineering design methodology adapted from industry best practices:

Problem Identification → Research → Conceptual Design → 
Detailed Design → Prototyping → Testing → Refinement → Implementation

Phase 1: Problem Identification

Objective: Clearly define the problem we're solving

Activities:

• Stakeholder interviews (farmers, municipal workers, industry experts)
• Site visits and observations
• Data collection on current solutions
• Problem statement formulation

Deliverables:

• Problem statement document
• Requirements specification
• Success criteria definition

Phase 2: Research & Analysis

Literature Review:

• Academic papers and journals
• Industry reports
• Patent searches
• Existing solutions analysis

Technical Research:

• Material properties and availability
• Component specifications
• Cost analysis
• Regulatory requirements

Tools Used:

• Google Scholar, IEEE Xplore
• Sri Lanka Standards Institution (SLSI) guidelines
• Local supplier catalogs

Phase 3: Conceptual Design

Brainstorming Techniques:

• Mind mapping
• SCAMPER method
• Morphological analysis

Concept Evaluation:

We use a weighted decision matrix:

$$ S_i = \sum_{j=1}^{n} w_j \times r_{ij} $$

Where:

• $S_i$ = Total score for concept $i$
• $w_j$ = Weight of criterion $j$
• $r_{ij}$ = Rating of concept $i$ for criterion $j$

Evaluation Criteria:

• Technical feasibility (weight: $0.25$)
• Cost effectiveness (weight: $0.20$)
• Environmental impact (weight: $0.15$)
• Ease of implementation (weight: $0.20$)
• Scalability (weight: $0.20$)

Phase 4: Detailed Design

CAD Modeling:

• SolidWorks for mechanical components
• Fusion 360 for assemblies
• AutoCAD for 2D drawings

Engineering Analysis:

Stress Analysis: For structural components, we verify:

$$ \sigma_{max} \lt \frac{\sigma_{yield}}{SF} $$

Where $SF$ = Safety Factor (typically 2-3 for static loads)

Thermal Analysis: For electronic systems:

$$ T_{junction} = T_{ambient} + P_{dissipated} \times R_{thermal} $$

Simulation Tools:

• ANSYS for FEA
• MATLAB/Simulink for control systems
• LTSpice for circuit simulation

Phase 5: Prototyping

Rapid Prototyping:

• 3D printing for plastic parts
• Laser cutting for sheet metal
• CNC machining for precision components

Electronics Prototyping:

• Breadboard testing
• PCB design (KiCAD)
• Arduino/Raspberry Pi for control

Documentation:

• Bill of Materials (BOM)
• Assembly instructions
• Wiring diagrams

Phase 6: Testing & Validation

Test Plan Development:

For each requirement, we define:

• Test procedure
• Acceptance criteria
• Measurement method
• Number of trials

Example Test Case:

Test ID: TC-001
Requirement: System shall operate continuously for 8 hours
Procedure: 
  1. Fully charge/fuel system
  2. Run at nominal load
  3. Monitor for failures
  4. Record runtime
Acceptance: Runtime ≥ 8 hours
Trials: 5 repetitions

Data Collection:

• Sensor measurements
• Performance metrics
• Failure modes
• User feedback

Phase 7: Refinement

Failure Mode Analysis:

We use FMEA (Failure Mode and Effects Analysis):

$$ RPN = Severity \times Occurrence \times Detection $$

Where RPN = Risk Priority Number (1-1000)

Iterative Improvement:

• Address high-RPN failure modes first
• Optimize based on test results
• Cost reduction without compromising quality

Phase 8: Implementation

Deployment Planning:

• Installation procedures
• User training materials
• Maintenance schedules
• Spare parts inventory

Documentation:

• User manual
• Technical specifications
• Maintenance guide
• Troubleshooting procedures

Tools & Software

Category	Tools
CAD	SolidWorks, Fusion 360, AutoCAD
Simulation	ANSYS, MATLAB, LTSpice
Programming	Python, C/C++, Arduino IDE
PCB Design	KiCAD, EasyEDA
Documentation	LaTeX, Markdown, Notion
Version Control	Git, GitHub
Project Management	Trello, Gantt charts

Quality Standards

We adhere to:

• ISO 9001 (Quality Management)
• ISO 14001 (Environmental Management)
• SLSI standards (where applicable)
• IEEE standards for electronics

Safety Considerations

All designs must:

• Include appropriate safety guards
• Have emergency stop mechanisms
• Use proper electrical isolation
• Comply with local safety regulations
• Include warning labels and instructions

Cost Management

Budget Tracking:

• Maintain detailed expense log
• Compare actual vs. estimated costs
• Identify cost-saving opportunities
• Justify any budget overruns

Cost Optimization:

• Use locally available materials when possible
• Consider manufacturing scalability
• Evaluate make vs. buy decisions
• Negotiate with suppliers

Sustainability

We consider:

• Material recyclability
• Energy efficiency
• Product lifetime
• End-of-life disposal
• Carbon footprint

Collaboration Tools

• Communication: WhatsApp group, weekly meetings
• File Sharing: Google Drive, GitHub
• Documentation: Shared Notion workspace
• Design Reviews: Weekly presentations to supervisor