Session 1: Intro to the Design Cycle
Session 1
Intro to the Design Cycle
Today's Goal
- Learn the 6-stage design cycle that structures this entire semester
- See how everything — safety, measurement, the launcher project — fits onto it
- This is the "why" of the whole course
Quick Poll
What comes to mind when you hear "the engineering process"?
(No wrong answers yet.)
Last Year vs. This Year
Freshman year: you learned tools — 2D/3D CAD (AutoCAD, OnShape).
This year: you learn the process those tools serve.
Last Year vs. This Year
Tools without process means you can draw it, but not design it.
The Design Cycle
Stage 1: Define
- Who's it for?
- What do they need?
- What are the constraints?
- What does success look like?
"A vague idea isn't a design problem yet."
Stage 2: Design
- Generate multiple alternatives
- Choose between them deliberately
- Commit to one before building
Stage 3: Build
Turn the chosen design into something that actually exists.
Physical or digital — it has to be real, not theoretical.
Stage 4: Test
Check the thing against the success criteria you defined.
Not against "does it feel done."
Stage 5: Reflect
Interpret the test evidence: what worked, what failed, and why?
Decide which earlier stage needs more work.
Stage 6: Iterate
Return to that stage and make one targeted change.
Then build and test again — not a random do-over.
Reflection Has Two Jobs
Inside the loop: interpret each test before deciding what to change.
At the end: explain what the whole project taught you and what carries forward.
Worked Example: Bike Helmet Strap
A rider's helmet strap keeps slipping loose. Let's walk the cycle.
| Stage | What it looks like |
|---|---|
| Define | The strap loosens mid-ride. It needs to stay snug without being uncomfortable. |
| Design | Sketch three buckle ideas instead of building the first one that comes to mind. |
| Build | Make a working version of the strongest concept. |
| Test | Put it under real load — does it actually hold, or just look like it should? |
| Reflect | The load test shows the buckle loses tension while the strap and anchors stay put, so the buckle is the part to change. |
| Iterate | Adjust the buckle tension, rebuild that part, and run the load test again. |
Notice: every stage here is a specific action, not a vague step.
Same Cycle, Bigger Project
This exact loop runs all semester — just with bigger stakes.
Same Cycle, Bigger Project
- Define/Design: frame a real problem before touching any tools
- Build: in the makerspace, with real materials
- Test/Reflect: use real data to decide what the result means
- Iterate: change the stage the evidence says needs work, then test again
- Final reflection: explain your choices and carry the learning forward
Reflection is not a box you reach once at the end — it is what turns every test into a reasoned next move.
Activity: Where Does It Go?
Here's the story: you and a friend are building a skateboard ramp for your driveway.
- Your friend shows you exactly how to keep your fingers clear of the circular saw blade before you're allowed to cut the plywood
- You measure the ramp's angle with a protractor to make sure it matches the sketch you drew
- You try out the finished ramp and measure how high it launches you
- You compare that test with your target height and conclude that the ramp is too tall — its width and surface held up
- You shave an inch off the height, then test the ramp again instead of tearing the whole thing apart
There's no single right answer for every item — some could fit more than one stage. Be ready to explain your reasoning.
Three Things to Remember
Reflect before you iterate.
Evidence first, interpretation second, targeted change third.
Three Things to Remember
Iterate ≠ starting over.
It means making one targeted change — not throwing out the whole design.
Three Things to Remember
Build isn't separate from Design.
Building is just acting on a design decision you already made.
Next Time
Session 2: Problem Framing
The stage most often skipped — and the one that matters most.
'F' → Fullscreen
Build
Today's "build" is conceptual. Here's the story: you and a friend are building a skateboard ramp for your driveway. Work with a partner to place each of the five moments below onto the design cycle. Agree on one stage — Define, Design, Build, Test, Reflect, or Iterate — that each moment fits best, and be ready to explain your reasoning. Some moments don't have a single clean answer, and that's intentional.
Where Does It Go?
- Your friend shows you exactly how to keep your fingers clear of the circular saw blade before you're allowed to cut the plywood
- You measure the ramp's angle with a protractor to make sure it matches the sketch you drew
- You try out the finished ramp and measure how high it launches you
- You compare that test with your target height and conclude that the ramp is too tall — its width and surface held up
- You shave an inch off the height, then test the ramp again instead of tearing the whole thing apart
For each moment, note which stage it belongs to and why. These are working notes for the pair discussion — the exit ticket below is what actually gets handed in, and it only asks you to write up 3 of the 5.
Checkpoint
Before moving on, compare your pair's reasoning against these three common sticking points.
- Reflect before you iterate
- Testing produces evidence. Reflection explains what that evidence means; only then do you choose a targeted change.
- Iterate ≠ starting over
- It means making one targeted change based on what you just learned — not throwing out the whole design.
- Build isn't separate from Design
- Building is just acting on a design decision you already made. They're connected, not two different jobs.
If your pair's placement for "measuring the ramp's angle" or "your friend showing you how to keep your fingers clear of the blade" doesn't match another pair's, that's expected — both items genuinely span more than one stage.
Reflection
This is today's exit ticket — complete it before you leave.
Pick any 3 of the 5 moments from the Build section above. For each one, name its best-fit stage and justify your choice in one sentence. Then answer both questions below.
- Which two stages of the design cycle do you think are easiest to confuse with each other? Name them, then give the one-sentence test you'd use to tell them apart.
- Session 2 is about defining a problem precisely before designing anything. Think of a problem you'd actually want to solve — can you state it without naming a solution anywhere in the sentence?
An activity can belong to more than one stage — if you think it does, say so and explain your reasoning.
Submit
Hand in your exit ticket before leaving class.