In recent years, development of Open Source Software has obtained significant
importance in the production of software products. Although, developers of Open Source Software
have developed software with functional competitiveness as compared to closed proprietary
software; computer users still prefer closed proprietary software than open source due its
usability strength.
On the other hand, once the usability of OSS is evaluated, it would be easier to develop and
implement an acceptable and qualitative product, since the software usability is considered to be
one of the most important quality factors. Thus, this work proposed a multistage fuzzy model
approach for evaluating the Open Source Software usability, which includes nine usability
characteristics to be taken into account when designing and implementing OSS software. The
model takes a project, developed in MATLAB and quantifies its usability. The Analytical
Hierarchy Process (AHP) technique was employed to verify the proposed model approach and to
rank its usability characteristics. These characteristics are sequenced according to its importance
as follows; learnability, understandability, efficiency, error prevention, memorability, operability,
familiarity, attractiveness, and usability-compliance.