Lesson at a Glance | He Tirohanga Whakamua
NgΔ WhΔinga Ako | Learning Intentions
Students will know
- The 5 distinct stages of Life Cycle Assessment (LCA).
- How planned obsolescence (perceived, functional, and technological) drives unnecessary consumption.
- That designing for long life and repairability is a deliberate technical choice, not an accident.
Students will demonstrate
- By drawing a complete, annotated Life Cycle Map for their chosen product area.
- By completing Design Journal Section 3 and identifying where environmental harm concentrates in their product's lifecycle.
Do Now | TΔ«matanga Whakaaro (10 min)
Think-Pair-Share:
"Why can you easily change a lightbulb or a double-AA battery in a torch, but replacing a smartphone battery requires heat guns, suction cups, and specialised screwdrivers?"
Unpack the answer: Older electronics were designed for user maintenance and modular repair. Modern electronics are often designed with glued enclosures to slim down device profiles and encourage users to replace the entire phone when battery capacity degrades after 2β3 years. This is a deliberate design choice.
The 5 Stages of Life Cycle Assessment (LCA) (15 min)
A Life Cycle Assessment tracks a product from "cradle to grave" (or "cradle to cradle"). Introduce the 5 stages:
1. Extraction
Mining raw minerals, harvesting timber, refining crude oil into plastic polymers.
2. Manufacturing
Refining, smelting, component assembly, high-temperature industrial processing.
3. Distribution
Shipping via container vessels, air freight, trucking to warehouses and retail outlets.
4. Use Phase
Electricity consumption, washing, maintenance, replacement parts during active life.
5. End-of-Life
Landfill, incineration, recycling, or environmental leakage into ecosystems.
Planned Obsolescence Simulation (15 min)
Case Analysis: The Cost of Obsolescence
Compare two design strategies for a wireless earbud product:
- Glued battery, non-replaceable.
- Lifespan: 24 months (battery degradation).
- Cost: $250 every 2 years = $1,250 over 10 years.
- E-waste: 5 pairs thrown in landfill.
- Clip-in battery ($20 replacement).
- Lifespan: 10 years (with 4 battery swaps).
- Cost: $300 + 4 Γ $20 = $380 over 10 years.
- E-waste: 1 pair + 4 tiny batteries recycled.
Key Question: Why do companies choose Design A? Because Design A generates 3.3Γ more revenue for the manufacturer while transferring the environmental cost onto the public and future generations.
π Design Journal β Section 3: Life Cycle Map
Students open their Design Journal and create Section 3:
Section 3 Requirements:
1. Annotated Life Cycle Diagram: Sketch or map the 5 stages for your chosen product area.
2. Harm Concentration: Highlight the single stage where the worst environmental or social impact occurs.
3. Obsolescence Diagnosis: Is your product designed with planned obsolescence? Identify whether it is functional (glued parts), technological (software drops), or perceived (fashion trends).
Exit Analysis | Ka Mutu Hoki (5 min)
Exit Ticket Question:
"In my chosen product area, the environmental harm concentrates mostly in Stage [1β5] because [Reason]. This is where my redesign will intervene."
Teacher Planning & Curriculum Alignment
NZ Curriculum Alignment (Technology β Phase 3 / Years 9β10):
- Technological Systems: Analyse inputs, transformations, and outputs across a complete technological life cycle.
- Nature of Technology: Critique the economic incentives behind planned obsolescence vs sustainable product stewardship.
Vocabulary: Life Cycle Assessment (LCA), cradle-to-grave, cradle-to-cradle, planned obsolescence, repairability index.