The increasing costs and complexity of maintaining IT environments has resulted in a focus on both Services Oriented Architectures (SOA) as well as model-based automation. By creating IT functions as modular building-blocks and automating common interaction patterns between them, IT can be made more flexible, easier to manage, and less costly to maintain. This paper presents Picasso, an architecture targeted at automating IT capabilities based on SOA and Model Driven Architecture (MDA) principles. Picasso structures IT capabilities as a set of services, each of which exposes a description of itself as a service model to the SOA. Service interactions are restricted to operations on the service models. Picasso thus balances a decentralized view of the world with the ability to re-use services in an automated manner. It provides service architects with a structured methodology and interaction patterns that can be used to create model based automation capabilities. 49 Pages