Welcome to Testing and Evaluation
Congratulations on reaching the final, crucial phase of your AS 2: Coursework – Product Development portfolio! You have analysed an existing commercial product, developed clever redesign concepts, and built your physical 3D prototype. Now comes the defining stage: Testing and Evaluation.
Many students make the mistake of thinking this section is just a quick summary saying "I made it, and it worked well." But in CCEA AS Level Technology and Design, testing and evaluation is an active, analytical investigation. This is your opportunity to demonstrate your critical thinking, measure real-world performance using hard data, and show how your redesign successfully solved the shortcomings of the original commercial product.
Unit Weighting Reminder: Unit AS 2 is worth 50% of your total AS award (and 20% of the full A Level award). High marks in Testing and Evaluation can significantly elevate your overall portfolio grade!
---1. The Core Purpose: Product Development Context
Before diving into testing, always remind yourself of the central brief for AS 2: Product Development.
Unlike an open design brief where you create something completely from scratch, AS 2 is specifically about identifying weaknesses in an existing commercial product and developing an improved outcome.
When you evaluate your finished prototype, your overarching question must always be:
"Did my new design successfully fix the flaws and limitations of the original commercial product?"
Quick Review – The 5 Pillars of AS 2 Evaluation:
• Pillar 1: Specification Testing – Direct, point-by-point testing against measurable criteria.
• Pillar 2: User & Third-Party Feedback – Verifiable testing with real users and clients.
• Pillar 3: Manufacturing & Material Appraisal – Critical review of your workshop methods, materials, and CAM processes.
• Pillar 4: Commercial Modifications – Technical proposals for industrial mass production.
• Pillar 5: Safety, Economics & Environment – Reviewing sustainability, lifecycle, and safety standards.
2. Testing Against the Product Design Specification (PDS)
Your original Product Design Specification (PDS) contains the measurable rules you set out to achieve. In this section, you must test your prototype against every single specification point.
Objective (Quantitative) vs Subjective (Qualitative) Testing
To score in the top mark bands, examiners require objective, measurable evidence rather than vague personal opinions.
• Subjective Testing (Weak): "The product feels light and seems strong enough." (This is merely an opinion and provides no scientific evidence).
• Objective Testing (Strong): "The specification stated the total mass must not exceed \(500\text{ g}\). When placed on a digital scale, the prototype measured \(438\text{ g}\), satisfying the criterion with a \(62\text{ g}\) safety margin."
Examples of Measurable Tests in AS 2:
• Dimensional Accuracy: Measuring critical dimensions using vernier callipers or micrometres to check tolerances (e.g., verifying a slot width is \(20\text{ mm} \pm 0.5\text{ mm}\)).
• Load & Structural Integrity: Applying a predetermined mass or force (e.g., \(10\text{ N}\) or \(5\text{ kg}\)) to test for deflection, joint failure, or material bending.
• Functional / Cycle Testing: Operating a hinge, switch, or mechanical linkage repeatedly (e.g., \(50\) consecutive opening/closing cycles) to check for binding, friction, or component wear.
• Ease of Assembly / Disassembly: Timing how long it takes a user to assemble, adjust, or replace a battery or modular component.
Key Takeaway: Always present your specification testing systematically in your portfolio. Include photographs of you physically measuring, weighing, or stress-testing the prototype alongside numerical tables of results.
---3. User, Client, and Third-Party Testing
As the designer, you are naturally biased—you know exactly how your product works and how to handle it carefully. That is why third-party testing is essential.
Who should test your prototype?
• The Target Market / User Group: If your product was redesigned for children, elderly users, or workshop technicians, individuals from that target demographic must test it.
• Primary Client / Stakeholder: The person or group who presented the initial product problem.
• Peer & Expert Review: Fellow designers or technical teachers evaluating mechanical action and finish.
Effective Methods for Gathering User Feedback:
• User-Trial Observations: Give the prototype to a user without explaining how to use it. Photograph or record their interaction. Do they struggle with grip? Are the controls intuitive? Is the balance comfortable?
• Targeted Questionnaires: Use structured rating scales (e.g., Rate the comfort of the handle from 1 to 5) combined with open-ended feedback questions (e.g., What was the most difficult part of adjusting the mechanism?).
• Ergonomic Assessments: Measure how comfortably the product fits human hand sizes (percentile data), viewing angles, and operational heights.
Key Takeaway: Document user testing with clear photographs showing real people interacting with your outcome, accompanied by direct quotes and analytical summaries of their feedback.
---4. Critical Evaluation of Redesign and Manufacture
This section is an honest, technical appraisal of how you built the prototype and how well the redesign performs compared to the original commercial item.
Evaluating the "Product Development" Success
Revisit the original commercial product you analysed at the start of AS 2:
• What were its key flaws? (e.g., brittle casing, poor grip, complex assembly, high part count).
• How did your redesign solve these flaws?
• Did your redesign introduce any new, unforeseen challenges?
Evaluating Materials and Processes Used in the Workshop
Critically assess the practical decisions made during the realisation stage:
• Material Selection: Did the acrylic, aluminium, plywood, or 3D printed PLA perform as expected? Were there issues with brittleness, rigidity, or surface finish?
• Manufacturing Techniques: How effective were your hand tools, machine tools (e.g., centre lathe, pillar drill), and CAM equipment (e.g., laser cutter, 3D printer, CNC router)?
• Accuracy & Tolerances: Did joints fit tightly? Did heat from laser cutting cause edge distortion? Did 3D printed layers cause dimensional variances?
5. Commercial Modifications and Industrial Manufacture
A school or college workshop prototype is rarely identical to a mass-produced commercial item. In this section, you explain how your design would be modified for large-scale industrial production.
Don't fall into the trap of saying: "If I had more time, I would make it neater." That is an evaluation of your personal workshop time, not an engineering proposal!
Industrial Considerations to Detail and Sketch:
• Manufacturing Processes: Propose industrial mass-production methods. If your prototype had a fabricated acrylic box, explain that the commercial version would be injection moulded from ABS or polypropylene.
• Design for Manufacture (DFM): Detail the technical changes needed for industrial tooling:
– Adding draft angles (e.g., \(1^\circ\) to \(2^\circ\)) to allow components to eject from moulds cleanly.
– Adding internal ribs and gussets to strengthen thin walls without adding excessive material.
– Specifying uniform wall thicknesses to prevent sink marks during cooling.
– Incorporating snap-fit joints or standardised screw bosses to reduce assembly time and eliminate glue.
• Scale of Production: Define the appropriate scale (e.g., batch production vs high-volume continuous production) and justify your tooling choices (e.g., CNC-machined hardened steel moulds vs aluminium tooling).
• Graphic Communication: Use clearly annotated 2D/3D sketches or CAD renders to illustrate these specific commercial modifications.
6. Environmental, Economic, and Safety Considerations
Modern product design demands responsible engineering. Evaluate your prototype through the lens of sustainability and regulatory standards.
1. Sustainability and Product Life Cycle (LCA)
• Materials & Recyclability: Are the polymers clearly marked with recycling codes (SPI codes)? Are incompatible materials easily separated at the end of product life?
• Design for Disassembly (DfD): Can components be unclipped or unscrewed for repair and recycling, or did the use of permanent adhesives prevent separation?
• Carbon Footprint & Material Efficiency: Has material wastage been minimised through nesting on sheet stock or lightweighting internal structures?
2. Economic Viability
• Direct vs Indirect Costs: Consider raw material costs, component standardisation (using standard \(M4\) bolts rather than custom fixings), and production cycle times.
• Commercial Competitiveness: Does the developed product offer better value or longer durability than the original commercial item it replaces?
3. Safety Standards and Legislation
• User Safety: Are there sharp edges, pinch points, exposed electrical connections, or loose small parts that could present hazards?
• Regulatory Compliance: Reference relevant standards applicable to your product type (e.g., UKCA / CE marking requirements, British Standards (BS EN) for toy safety, electrical insulation, or stability).
7. Common Pitfalls and Examiner Tips
Top 4 Pitfalls Identified in CCEA Examiner Reports:
1. The "Story of What I Made" (Descriptive Diary):
Writing a chronological summary of what you did in the workshop. Solution: Focus 100% on critical analysis and data comparison.
2. Zero Quantitative Data:
Using only generic words like "good", "strong", or "effective". Solution: Provide numbers, measurements, weights, tolerances, and test times in structured tables.
3. Forgetting the Original Product:
Failing to explain how your redesign improved upon the original product's flaws. Solution: Include a dedicated comparison section between the original commercial product and your new prototype.
4. Vague Recommendations for Improvement:
Writing statements like "I would make it out of plastic next time." Solution: Specify the exact polymer (e.g., High-Impact Polystyrene - HIPS), the manufacturing process (e.g., vacuum forming or injection moulding), and provide annotated sketches showing tooling features like draft angles and split lines.
8. Quick Revision Checklist for Your Portfolio
Before submitting your Testing and Evaluation section, confirm you have included:
• [ ] A complete review against every point in your original Product Design Specification.
• [ ] Quantitative test data (measurements, weights, loads, times) displayed in tables and charts.
• [ ] Photographic evidence of physical testing taking place.
• [ ] Third-party / user-trial feedback with direct quotes, user surveys, and ergonomic analysis.
• [ ] A clear appraisal of how the redesign solves the original commercial product's flaws.
• [ ] An honest critical review of the materials and workshop techniques used.
• [ ] Detailed, annotated sketches / CAD models showing modifications for industrial mass manufacture (tooling, draft angles, wall thickness, mould design).
• [ ] Evaluation of environmental impact, recyclability, life cycle, and safety standards.