Learning Targets
- Identify the most important issue shown by testing.
- Choose a targeted revision instead of random changes.
- Plan or run a retest to check whether the revision helped.
IED Unit 4 • Lesson 4.20
Iteration and Prototype Revision
Focus question: How do engineers decide what to change after testing a prototype?
Mission Briefing
Today’s Plan
Use this page with the lesson presentation, your engineering notebook, and the tools or evidence assigned for Revise the Prototype from Test Evidence.
Success Looks Like
You can choose a prototype revision based on test evidence and explain why the change should improve performance.
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Opening Prompt
How do engineers decide what to change after testing a prototype?
Connect your response to the decision, evidence, or quality standard required for Revise the Prototype from Test Evidence.
Reveal: useful engineering move
This lesson is ready to move forward when the evidence meets this standard: The revision is linked to a measured weakness and does not introduce an undocumented new problem.
Core Skill
What We Are Practicing
Iteration should be driven by test evidence.
The best change is usually the one that addresses the biggest performance or reliability issue.
A revision is not complete until it is documented and checked again.
Your Task
Revise the Prototype from Test Evidence
Select the highest-priority weakness, make a controlled design change, and verify that the system still functions.
- Identify the test result that most limits success.
- Determine the likely cause and propose one targeted revision.
- Implement and document the change.
- Run a focused verification check using the earlier test method when possible.
Quality check: The revision is linked to a measured weakness and does not introduce an undocumented new problem.
Lesson Interactive
Prioritize a Prototype Revision
Use failure evidence to select the highest-impact revision first.
Test findings
- The guide binds during 2 of 5 trials.
- The paint color is uneven.
- The mechanism is 3 g heavier than predicted.
- The labels use two font sizes.
First revision priority
Revise the failure that blocks reliable function before addressing cosmetic issues.
What You Will Submit
Prototype Revision Record
Submission standard: The revision is linked to a measured weakness and does not introduce an undocumented new problem.
Resources
Lesson Resources
Lesson 4.20 PowerPoint
Use the lesson slides for guided practice, interactive checks, and the exit ticket.
Introduction to Engineering Design
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