<p><b>Abstract</b>—In this paper, we propose a faceted requirement classification scheme for analyzing heterogeneous requirements. The representation of vague requirements is based on Zadeh's canonical form in test-score semantics and an extension of the notion of soft conditions. The trade-off among vague requirements is analyzed by identifying the relationship between requirements, which could be either conflicting, irrelevant, cooperative, counterbalance, or independent. Parameterized aggregation operators, <it>fuzzy and/or</it>, are selected to combine individual requirements. An extended hierarchical aggregation structure is proposed to establish a four-level requirements hierarchy to facilitate requirements and criticalities aggregation through the <it>fuzzy and/or</it>. A compromise overall requirement can be obtained through the aggregation of individual requirements based on the requirements hierarchy. The proposed approach provides a framework for formally analyzing and modeling conflicts between requirements, and for users to better understand relationships among their requirements.</p>

Vague requirements, requirements specifications, requirements trade-off analysis, requirements classification, fuzzy logic.

Jonathan Lee, Jong-Yih Kuo, "New Approach to Requirements Trade-Off Analysis for Complex Systems", IEEE Transactions on Knowledge & Data Engineering, vol. 10, no. , pp. 551-562, July/August 1998, doi:10.1109/69.706056