Thinking Tools/New car decision matrix

This decision matrix can be used to choose among several new car alternatives being considered for purchase.

	Mazda 6	Nissan Altima	Nissan Maxima
Safety High = 5	5 Cell contribution is 5x5=25	4	5
Reliability High = 5	5	3	5
Low Cost Medium = 4	4	4	2
Space Medium = 4	4	4	5
Service Medium =4	5	4	4
Performance Low = 2	5	4	5
Aesthetics Low = 2	5	3	5
Total:	122	97	114

Begin by creating an affinity diagram on the topic “What is important to consider when choosing a new car”. Using the resulting affinity diagram as a starting point, create a tree diagram with the topic “What decision criteria will be used to choose a new car”.

Each row label represents a decision criterion identified from the tree diagram. The importance of each criterion is determined, quantified and recorded. Here high importance is assigned a weight of 5. Each column represents an alternative being evaluated, in this case three different car models. The rating of each alternative for each criterion is decided, quantified, and recorded in the corresponding cell. For example, the Mazda 6 is high in safety, so it is rated 5. The contribution of that rating is calculated as the score (5) multiplied by the criterion weight (5) for a total of 25 for that cell. The total score of each alternative is computed by summing the contribution of each cell in the column representing that alternative. Here the Mazda 6 gets the highest score of 122.