Praxis I: Rigid Pipe Attachment for Water Bottle Filling and Washing at Chestnut Residence

Pairwise Comparison - Converging

Our use of a pairwise comparison matrix allowed us to simplify our converging process, but the justifications accompanying it could have been stronger. During the converging process, we needed to gather data on our designs in order to compare them against evaluation criteria, or to verify them against requirements. However, we had 15 requirements, which would have taken more than the time we were able to spend on this project. We used the pairwise comparison matrix, shown below, to prioritize the requirements and select the five most important ones to verify. This allowed us to prioritize our requirements, and allowed us to simplify the verification process by only verifying design concepts against the most essential requirements.

However, the pairwise comparison matrix itself does not provide a justification for the prioritization of requirements. Each comparison in the matrix is based on intuition or an unarticulated perception that a certain requirement is more important than another. Thus, the results of a pairwise comparison matrix still needed to be justified. We did attempt to justify the importance of the top five requirements as shown in the design report extract above, but these justifications only give general justification of the importance of each requirement in isolation. They did not justify why other requirements (i.e., those ranked below the top 5) did not need to be tested. A stronger justification would have explained not just why certain requirements are important in general, but also what makes them more important than all the others. Thus, the pairwise comparison matrix can serve as a useful tool for simplifying a process, but only if its results are accompanied by sufficient justifications.