Impact of Usability for Particle Accelerator Software Tools Analyzing Availability and Reliability

Abstract: The importance of considering usability when developing software is widely recognized in literature. This non-functional system aspect focuses on the ease, effectiveness and efficiency of handling a system. However, usability cannot be defined as a specific system aspect since it depends on the field of application. In this work, the impact of usability for accelerator tools targeting availability and reliability analysis is investigated by further developing the already existing software tool Availsim. The tool, although proven to be unique by accounting for special accelerator complexities not possible to model with commercial software, is not used across facilities due to constraints caused by previous modifications. The study was conducted in collaboration with the European Spallation Source ERIC, a multidisciplinary research center based on the world’s most powerful neutron source, currently being built in Lund, Sweden. The work was conducted in the safety group within the accelerator division, where the availability and reliability studies were performed. Design Science Research was used as research methodology to answer how the proposed tool can help improving the usability for the analysis domain, along with to identify existing usability issues in the field. To obtain an overview of the current field, three questionnaires were sent out and one interview was conducted, listing important properties to consider for the tool to be developed along with how usability is perceived in the accelerator field of analysis. The developed software tool was evaluated with After Scenario Questionnaire and the System Usability Scale, two standardized ways of measuring usability along with custom made statements, explicitly targeting important attributes found when questioning the researchers. The result highlighted issues in the current field, listing multiple tools used for the analysis along with their positive and negative aspects, indicating a lengthy and tedious process in obtaining the required analysis results. It was also found that the adapted Availsim version improves usability of the previous versions, listing specific attributes that could be identified as correlating to the improved usability, fulfilling the purpose of the study. However, results indicate existing commercial tools obtained higher scores regarding the standardized tests targeting usability compared to the new Availsim version, pointing towards room for improvements.