Comparing AHP and CBA as Decision Methods to Resolve the Choosing Problem in Detailed Design

Multicriteria decision-making (MCDM) methods can help designers address the choosing problem in building detailed design. Many, however, appear to assume that all methods are equivalent. This paper argues that differences between MCDM methods matter. The first contribution of this paper is differentiating between the analytical hierarchy process (AHP) and choosing by advantages (CBA) by comparing them through an example. The second contribution is explaining why CBA is superior to AHP for this context. In summary, CBA (1) provides a more context-based analysis than AHP, (2) does not incorporate conflicting judgments for weighing factors as AHP does, (3) does not assume linear trade-offs between factors as AHP does, (4) does not assume that factors have zero as a natural scale as AHP does, (5) focuses on differentiating between alternatives more than AHP, (6) maintains the result of the decision when nondifferentiating factors are removed, whereas AHP may not, and (7) defers subjective judgments until late in the decision-making process, whereas AHP requires expressing them earlier. This presents a significant research finding, considering the wide use of AHP. Further research is needed to assess what range of design decisions CBA supports.