Many Off-The-Shelf Software (OTSS) assessment techniques have been proposed, most of them using criteria related to standard quality models. However, these techniques are not as useful to evaluate and compare alternative OTSS as solutions to specific process-driven organizational changes. This article proposes PBEC-OTSS (Process-Based Evaluation and Comparison of OTSS), a technique for evaluating and comparing OTSS regarding impact in the organization, based on process models, and using fuzzy decision making systems. The technique was compared with an Ad-Hoc approach (systemized from the literature) in an experimental study with IT professionals, some new to BPM and some experts; the experts obtained similarly good results with either approach, but the novice professionals obtained better results with PBEC-OTSS than with Ad-Hoc. These results suggest that organizations can improve their Business/IT alignment with this technique even if no process experts are available.