Skip to content

Design Decision Matrix

Run the Design Decision Matrix MicroSim Fullscreen
Edit in the p5.js Editor

About This MicroSim

A decision matrix compares designs fairly. Give each quality (criterion) a weight from 0 to 5 for how much it matters to you, give each design a score from 1 to 5 on that quality, then multiply and add:

\[ \text{weighted total} = \sum (\text{weight} \times \text{score}) \]

The bar chart shows each design's weighted total, and the winner gets a gold outline and a star. The matrix below the chart holds the weight sliders and a score menu for each design.

The Sensitivity button asks a useful question: how close was this decision? It finds the smallest change to a single weight that would let another design catch up, and reports the weight at which they tie. If no weight change from 0 to 5 can flip the winner, the choice is robust.

The Worked example preset loads the chapter's bedside clock comparison: readability 4, cost 2, power 1, accuracy 3 (user experience 0), which gives the LED clock 43 points and the round color watch 37.

How to Use

  1. Choose a Preset: the worked example, four desk clock designs, wearable priorities, or a blank matrix of 3s.
  2. Drag the Weight sliders to match your own priorities.
  3. Change any score with its menu.
  4. Press Sensitivity to see which weight the decision depends on most. (Any change clears the old sensitivity result, so press it again after editing.)

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

1
2
3
4
<iframe src="https://dmccreary.github.io/clocks-and-watches/sims/design-decision-matrix/main.html"
        height="547px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (Clocks and Watches with AI)

Duration

20 minutes

Prerequisites

  • Design trade-offs (Chapter 20)
  • Multiplying and adding weighted values

Learning Objectives

Students will be able to:

  • Evaluate competing clock designs with a weighted decision matrix
  • Justify a choice by naming the weights that decide it
  • Judge whether a decision is robust or would flip with a small change in priorities

Activities

  1. Check the worked example (4 min): Load the worked example and verify the totals of 43 and 37 by hand. Press Sensitivity. Why is the LED clock a robust choice here?
  2. Change the user (6 min): Load Wearable priorities. Which design wins now, and which two weights matter most? Press Sensitivity and explain the result in one sentence.
  3. Your own decision (10 min): Load the blank matrix. Decide what Designs A to D are (for example, four clocks from this book you could build) and score each one. Set weights that match your priorities, find the winner, run Sensitivity, and write a short justification that names your two heaviest weights.

Assessment

  • The student calculates a weighted total by hand and matches the chart.
  • The student explains how a change in priorities (weights) can reverse a decision.
  • The student's written justification uses the sensitivity result to defend the choice.

References

  1. Decision matrix - Wikipedia article on weighted decision matrices.
  2. Pugh method - Wikipedia article on the engineering decision-matrix method for comparing concepts.
  3. Sensitivity analysis - Wikipedia article on testing how much an answer depends on its inputs.
  4. Trade-off - Wikipedia article on giving up one quality to gain another.