Abstract-Service level management (SLM) is a challenge in a distributed systems environment because all processes should provide a consistent, reliable, and predictable service delivery. Early 1990s, most organizations established few service-level agreements (SLA) as the key performance indicators (KPI) but it was difficult to measure or monitor them in a distributed systems environment. The strength of Information Technology Infrastructure Library (ITIL) is the approach of integrating the SLM with the support processes at strategic, tactical, and operational levels. This paper focuses on implementing ITIL guidelines at an operational level for service desk, incidents, problems, and change management. The ITIL framework only provides guidelines, so a service organization needs to explore a methodology for evaluating existing service support processes and implementing ITIL guidelines for improvements. To this end, we investigate upon how to apply the ITIL framework for reengineering of IT service support process in an organization. The approach is actually implemented at a dentalcare service provider with ten dental clinics connected in Wide Area Network (WAN) and the data is collected into a central server in the main dental center. We first started with the process mapping, and then moved towards reengineering following ITIL guidelines, while collecting the results in key performance areas before and after the process reengineering. This paper used questionnaires, document reviews, archival records and observation techniques for collecting the data. The results demonstrated improvements in differing magnitudes. Some ststistical analysis such as mean and variance together with t-value distribution and null hypothesis were also developed to determine the quality of results. The paper is cautious about the limited scope of audience and the questionnaire which may compromise the results; however, the approach is useful in obtaining significant improvements when a company invests in integrating ITIL guidelines in to service support processes.