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01. Why Use a Decision Matrix?
Moving from the divergent thinking phase (many wild ideas) to the convergent phase (one selected concept) requires a rigorous, objective mechanism. Decision matrices (or Pugh concepts matrices) help teams:
- Remove personal bias and emotional attachment from design selection.
- Evaluate concepts systematically against the Program of Requirements (POR).
- Identify the strengths and weaknesses of different approaches, potentially leading to a hybrid solution.
- Provide a clear, defensible rationale for the final design direction to stakeholders.
02. Building the Matrix
Follow these steps to construct and use a weighted decision matrix:
- Define Criteria: Extract key requirements from your POR and stakeholder analysis (e.g., Cost, Collaboration Potential, Clinical Integration, Flexibility, Neuro-inclusive Design).
- Assign Weights: Determine the relative importance of each criterion. Use a scale (e.g., 1-5), where 5 is critical/mandatory and 1 is a "nice-to-have".
- Establish a Baseline: Select one concept (often the most standard or conventional approach) to serve as the baseline or "datum".
- Score Concepts: Evaluate all other concepts against the baseline for each criterion. Use a simple scale:
- +1 (Better than baseline)
- 0 (Same as baseline)
- -1 (Worse than baseline)
- Calculate Scores: Multiply the rating by the weight for each cell, then sum the columns.
03. Example Framework
| Evaluation Criteria |
Weight (1-5) |
Concept A (Baseline) |
Concept B (Hub & Spoke) |
Concept C (Open Plan) |
| Promotes Collaboration |
5 |
0 |
+1 (5) |
+1 (5) |
| Cost/Constructability |
4 |
0 |
-1 (-4) |
0 (0) |
| Acoustic Privacy |
4 |
0 |
0 (0) |
-1 (-4) |
| Flexibility for Future Growth |
3 |
0 |
+1 (3) |
+1 (3) |
| Neuro-inclusive Environment |
5 |
0 |
+1 (5) |
-1 (-5) |
| TOTAL SCORE |
0 |
+9 |
-1 |
In this scenario, Concept B is the clear winner, but the team might look at Concept C to see if its collaboration benefits can be integrated while mitigating acoustic issues.