—In the majority of today’s IT organizations, Service Level Agreements (SLAs) are an important means for underpinning IT service provisioning by clearly defined Quality of Service (QoS) parameters as well as service costs and violation penalties. The management of those SLAs is the main subject addressed by the discipline of Service Level Management (SLM) which covers several activities vital for the deployment of customer-oriented, high-quality and well-performing IT services. This paper analyzes and compares two of the most important SLM frameworks available in business-driven IT Management: the IT Infrastructure Library (ITIL) with its SLM reference process and the NGOSS SLA Management Handbook. In order to deliver significant and helpful results, we derive a set of evaluation criteria from a realistic IT scenario. These criteria are applied to ITIL and NGOSS in order to elaborate possible areas of conflict as well as complementary fields and unaddressed issues. The results ...