What is Composability

This chapter provides an overview from a business perspective of some of the important non-functional properties of services, such as availability, performance, and security. It discusses the typical metrics for these non-functional properties which are used in service level agreements to measure and report how well a service is meeting customer expectations. It briefly discusses cost considerations for service providers and consumers, as some levels of service are expensive to attain. The goal is to provide the reader with an understanding of these non-functional properties, their measures and cost implications, and related interesting research opportunities.