Commercial off-The Shelf (COTS) products are increasingly used by organizations to automate (partial o totally) their business processes. Choosing the proper combination of components is not a trivial task, usually requiring thorough assessment; existing techniques address selection of ERP's, TPS and other kinds of business software, but do not extend to general COTS-based systems. This article describes the extension of the existing PBEC-OTSS (Process-Based Evaluation and Comparison Off-the-Shelf software), originally published in 2013, to enable measuring stability of recommended solutions under changes in information. An experimental study was conducted to compare the updated technique with the original one; study participants were IT professionals and an expert; the case study is a real scenario from a Chilean public sector institution; and effort, satisfaction and assessment quality were measured. The study showed that both techniques yield similar results to the expert, but PBEC-OTSS presented better results for non-expert professionals. It remains to be explored why acceptance was correlated with difficulty rather than effort.