IED course icon
IED Unit 5 • Lesson 5.6

Decision Matrix and Final Concept Selection

Focus question: How can engineers choose a design concept using evidence instead of personal preference?

Your lesson guide

Objective

Use design criteria to compare multiple concepts. Score concepts using a decision matrix. Justify the selected concept with evidence and tradeoffs.

Materials

For the online work: a browser and your engineering notebook. Follow the activity’s materials list for any physical build, and get teacher approval before using equipment.

Plan your time

Suggested work block: 45–60 minutes. Physical builds and projects may span several classes; follow your teacher’s schedule.

Mission Briefing

Today’s Plan

Use this page with the lesson presentation, your engineering notebook, and the tools or evidence assigned for Select the Capstone Concept with Evidence.

Learning Targets

  • Use design criteria to compare multiple concepts.
  • Score concepts using a decision matrix.
  • Justify the selected concept with evidence and tradeoffs.

Success Looks Like

You can use a decision matrix to compare concepts and justify a final concept selection.

LaunchLearnApplyCheckSubmit
Opening Prompt

How can engineers choose a design concept using evidence instead of personal preference?

Connect your response to the decision, evidence, or quality standard required for Select the Capstone Concept with Evidence.

Reveal: useful engineering move

This lesson is ready to move forward when the evidence meets this standard: The selected concept is supported by the matrix and the justification acknowledges weak evidence or risk.

Core Skill

What We Are Practicing

Key Idea 1

A decision matrix makes concept selection more transparent.

Key Idea 2

Scores should connect to criteria, not popularity.

Key Idea 3

The best concept is the one that best fits the defined problem and constraints.

Your Task

Select the Capstone Concept with Evidence

Use weighted criteria and research evidence to compare the concepts and choose a defensible direction.

  1. Confirm that the matrix criteria match the design brief.
  2. Set and justify criterion weights.
  3. Score each concept using known evidence.
  4. Select the concept and document uncertainty or needed proof.

Quality check: The selected concept is supported by the matrix and the justification acknowledges weak evidence or risk.

Lesson Interactive

Select a Concept with a Weighted Decision Matrix

Weights represent criterion importance. Calculate each concept’s weighted total, then select the highest-scoring concept.

ConceptUsability ×4Reliability ×3Sustainability ×2Weighted total
A: Quarter-turn cam345—
B: Captive sliding pin534—
C: Magnetic latch452—
Multiply each rating by its weight, add the products, and use the total—not personal preference.
What You Will Submit

Concept Selection Evidence

  • A completed decision matrix.
  • A short evidence-based selection justification.

Submission standard: The selected concept is supported by the matrix and the justification acknowledges weak evidence or risk.

Resources

Lesson Resources

Presentation

Lesson 5.6 PowerPoint

Use the lesson slides for guided practice, interactive checks, and the exit ticket.

Course Hub

Introduction to Engineering Design

Return to the IED course hub for units, resources, certifications, and current course information.

Build your lesson report

Checkpoint: is your evidence ready?
  • Check calculations, units, labels, and measurements against the activity requirements.
  • Record what actually happened, including unexpected results.
  • Explain what you changed and why; attach required drawings, photos, CAD, or code in your classroom assignment.

Submit the evidence specified in the activity and your classroom assignment. The report below collects your notes, calculations, observations, and reflections; attach any required drawings, photos, CAD, or code separately.

A PDF download is not a submission. Review it, then upload it and any required attachments through your classroom assignment system.