Recently, Service Level Management(SLM) including SLA has been developing to manage the level of information systems service. Although previous SLA studies have provided the conceptual model and critical success factors, the studies have not tested the effectiveness of the SLA by way of the empirical study. In this study, we applied an innovation decision making theory to our model and tested an empirical study using of a firm survey data. We suggested a SLM model, which consists of SLA planning, application, management dimensions. We found that the SLM's management stage has an impact on performance, whereas SLM's planning and application has not. At each sub dimensional analysis, there are found that adequate SLA indicators in the application stage influences performance and change management and feedback & reporting in the management stage influence performance.