A Semi-automated Decision Support Tool for Requirements Trade-Off Analysis

System designers and requirements analysts face many competing requirements, such as performance, usability, security, cost, and so forth. To make trade-offs among requirements, ideally analysts would like to quantitatively measure consequences of alternative solutions on requirements. However, during the early stages of requirements and system design, it is hard to quantitatively measure all factors and quantify stakeholders´ preferences. The Even Swaps method is a technique developed in management science to assist in multi-criteria decision making which allows the use of available but potentially incomplete quantitative and qualitative measures. It teases out the need to elicit importance weights of requirements. Instead, stakeholders are asked how much they would relax one objective to better achieve another. We apply the Even Swaps technique to requirements trade-offs, and supplement it with an algorithm that automates the decision analysis process. The algorithm fins the most distinguishable pair of alternatives and suggests the next requirements to be swapped to stakeholders.