Analysis of the Relation between Service Parameters for Service Level Management and System Utilization

System utilization was investigated with the aim of selecting appropriate service parameters for defining the quality of information systems such as SLA (service level agreement). This investigation is based on the hypothesis that parameters having a strong influence on user satisfaction depend on how the system is used. Accordingly, the parameters for availability and responsiveness, which are known as the two major factors in SLA, were investigated. First, it is explained that parameters having a strong impact on user satisfaction are not common among information systems. Next, three parameters for availability (mean time between halt, mean time to restore, and both of them) and ones for responsiveness (mean time, maximum time, and variance) were introduced. To analyze the relation between these service parameters and system utilization, a questionnaire about system utilization was designed and administered to several experienced system engineers. Quantification theory type II was applied to the results of this questionnaire, and the validity of the hypothesis was demonstrated. The results also classified information systems into six groups in terms of availability and responsiveness. The characteristics of each system group were also clarified.