I. Introduction: Framing the Problem (Tell them what you'll teach)

The Hook: The Paradox of Constraints

Question: When you start a complex project, do more options make the solution better, or does having strict limits (time, budget, resources) force you to be more innovative?

In product development, engineering, and even cooking, constraints are not obstacles—they are the boundaries that define success. Today, we're not just building; we're optimizing resource allocation to solve a physical challenge.

Learning Objectives (Success Criteria)

By the end of this lesson, you will be able to:

1. Analyze complex problems and define core constraints (time, material, performance).
2. Apply the iterative Design Thinking process (ideate, prototype, test, iterate) to a physical construction challenge.
3. Optimize a functional design prototype based on performance data and resource metrics.

II. Core Content and Design Sprint (Teach it)

Phase 1: I Do - Defining the Challenge and Constraints (Modeling)

Instructor Model/Guided Analysis: The challenge today is to build a robust cantilever structure.

A cantilever is a rigid structural element, such as a beam or plate, anchored at only one end to a (usually vertical) support from which it protrudes. Think of a balcony or a diving board.

The Core Challenge

Design and build a stable cantilever that extends at least 10 cm horizontally from a fixed base (e.g., the edge of a table or box) and can support the maximum possible weight for a minimum of 10 seconds.

Key Performance Indicators (KPIs) & Constraints

We will model the professional design process by assigning strict constraints:

1. Performance Constraint: Must hold a minimum of 10 units of weight (e.g., 10 pennies) at the furthest point (10 cm mark).
2. Resource Constraint (Budget): You have a strict budget for materials. You must track every unit used (e.g., 1 straw = 1 unit, 10 cm of tape = 1 unit, 1 craft stick = 2 units). The goal is maximum weight supported per unit of material cost.
3. Time Constraint: Initial ideation and prototype build must be completed within 30 minutes.

Phase 2: We Do - Ideation and Initial Prototype (Collaborative Practice)

Activity: Design Sprint Stage 1 (Ideation & Sketching)

Goal: Generate multiple potential structural designs before committing to the build.

Process (Think-Pair-Share Adaption):

• Think (10 minutes): Sketch 3 distinct structural concepts in your design journal. Focus on triangle bracing, tension vs. compression, and maximizing material efficiency. Consider how professional cantilevers (bridges, buildings) are engineered.
• Critique (5 minutes): Self-critique the three designs using the KPIs. Which design uses the fewest materials while appearing the most structurally sound? Select the single best concept for the initial build.
• Share (Verbal Check-in / Reflection): Briefly explain your chosen design strategy. (In a classroom/training setting, learners would share with a partner. In a solo context, the learner explains the choice in their journal, listing the estimated material count.)

Phase 3: You Do - Build, Test, and Iterate (Independent Application)

Activity: The 30-Minute Build Challenge

1. Initial Build (15 minutes): Using your chosen design, construct the cantilever structure, ensuring the base is firmly anchored (taped) to the surface and the structure extends at least 10 cm outward. Track every material unit used meticulously.
2. Test 1 (5 minutes): Place weights one by one onto the furthest 10cm point until the structure fails (bends excessively or collapses). Record the maximum weight supported and the total resource cost (units used).
3. Data Analysis (5 minutes): Calculate the Efficiency Score: Max Weight Supported / Total Resource Cost. Analyze the failure point: Where did the structure break? Was it compression (squishing) or tension (pulling apart)?
4. Iteration (5 minutes): Based on the data and failure analysis, immediately apply one major modification to the structure to improve its efficiency score (e.g., reinforce the failure point, reduce material in non-load-bearing areas, change the bracing angle).

Success Criteria Check:

Did the final iteration achieve a higher Efficiency Score than the initial prototype? This demonstrates successful design iteration based on empirical evidence.

III. Conclusion: Reflection and Application (Tell them what you taught)

Recap and Discussion (Formative Assessment)

Review the process by answering the following reflection questions (verbally or in the journal):

• How did the initial constraints (especially the resource budget) immediately affect your design strategy?
• Was your first assumption about structural integrity correct? What did the failure test teach you about the material properties?
• In what real-world scenarios (e.g., agile project management, supply chain optimization) is the "Max Performance/Min Resource" efficiency metric crucial?

Summative Assessment: Final Design Documentation

The learner will complete a short report summarizing the project results, focusing on the iterative process, demonstrating mastery of Objective 2 and 3.

Deliverables:

1. Photo/Sketch of the final, optimized cantilever.
2. Performance Summary Table:

   Prototype	Max Weight Held (Units)	Total Resource Cost (Units)	Efficiency Score (W/C)
   Initial Build	[Data]	[Data]	[Data]
   Final Iteration	[Data]	[Data]	[Data]

3. Reflection Paragraph: Describe the single most effective change you made in the iteration phase and why that change led to a higher efficiency score.

Differentiation and Extension Activities

Scaffolding (For foundational problem solvers):

• Simplify Constraints: Remove the Resource Constraint calculation entirely for the first build. Focus only on building a successful structure that meets the 10cm/10 units performance metric. Introduce the resource constraint only for the second iteration.

Extension (For advanced builders/trainers):

• Budgetary Constraint: Assign monetary value to materials (e.g., tape is expensive, straws are cheap). The goal is now to achieve the required performance while minimizing monetary expenditure, requiring trade-offs between cheap materials (potentially less stable) and expensive materials (high performance).
• Mass Production Optimization: The learner must create a "Build Guide" for their optimized design so that someone else could replicate it exactly. This forces precise measurement and standardization, simulating quality control processes.