This IDC study presents a vendor assessment of providers offering managed security services (MSS) through the IDC MarketScape model. The assessment reviews both quantitative and qualitative characteristics that define current market demands and expected buyer needs for MSS. The evaluation is based on a comprehensive and rigorous framework that assesses how each vendor stacks up to one another, and the framework highlights the key factors that are expected to be the most significant for achieving success in the MSS market over the short term and the long term.