Complex Event Processing (CEP) is a powerful technology for implementing real time applications. It offers efficient processing of occurring information pieces, so called events, based on an architecture that provides strong decoupling of its components: event producer, event processors and event consumer [4]. For this CEP is seen as an important contribution in future information systems. CEP applications already have been successfully applied in different fields of industry like finance, logistics and manufacturing 1 . Vendors of CEP products promise agile real time systems as you are able to change business logic on the fly. But this promise brings risks. Without comprehensive quality assurance changing small pieces of these complex systems can lead to unpredictable errors. Modern agile methodologies rely on strong quality assurance techniques like test driven development, continuous integration or automated user acceptance tests [27]. These methodologies will also be important in the development of CEP applications. This paper gives an overview about what requirements CEP products will have to meet to support up to date software quality assurance.