Gartner

Testing services have been separated out as a distinct practice area for building and managing testing areas — not only in terms of core testing services, such as unit, system and regression, but also other areas, such as:

• Building and deploying services (from packaged application to appliance and compliance testing services)
• Testing consultancy services (from strategy and business process to tooling and test infrastructure services)
• Managed testing services (from managing the test infrastructure and services to fully managed testing on demand services.”

- Gartner, Inc. Market Overview of Application Testing - Service Providers, Frances Karamouzis, Gilbert van der Heiden ,18 November 2008