Confiabilidade de software e qualidade da experiência do usuário: Um estudo quanti-qualitativo

Abstract

Software reliability studies have predominantly focused on only quantitatively evaluating system reliability, especially user applications. However, such an approach may not represent the actual Quality of Experience (QoE) of users. To improve users’ QoE, it is important to understand how they perceive system failures. In this work, software reliability analyzes were performed considering quantitative and qualitative factors, both related to Quality of Service (QoS) and users’ QoE. In order to evaluate the users’ QoE regarding the reliability of the investigated software, a questionnaire was elaborated with scenarios describing hypothetical but realistic situations of computer use in several situations in which software failures occur. Through the questionnaire questions, it was evaluated the reliability of software estimated by classical QoS-based methods, which approximates the users’ perception of the reliability of the analyzed software (QoE). The same questionnaire was applied both online and in person, aiming to compare the results of both approaches (oriented to QoS and QoE). In order to do this, we investigated the most relevant influence factors in the users’ QoE regarding software reliability for the use scenarios studied, using ten emotional dimensions. By performing a factorial analysis, it was observed that the ten dimensions evaluated were related to only one factor, the dimensions of stress, punctuality and patience being the three dimensions of greater relevance. Using such dimensions, an analytical model was proposed to estimate the reliability of software based on QoE, as well as an analytical model was adjusted using the most relevant dimensions pointed out by Test t. The results show that the most relevant dimensions indicated by the t-Test (Satisfaction and Tolerance) were the analytical model that presented the result closest to the users’ perception regarding software reliability. In addition, it has been observed that the Mean Time Between Failures (MTBF) and the consequence generated by the occurrence of a failure are factors of influence of QoE that negatively affect the perception of the users in relation to the reliability of software. Finally, it was observed that the result of calculating the reliability of a software considering only aspects of QoS is not compatible with the QoE of the users in relation to the reliability of the software used.