The SOA Innovation Lab has investigated the use of standard software packages in a service-oriented context. As a result, we present a holistic approach for developing a service-oriented enterprise architecture with custom and standard software packages. It starts on enterprise level with the identification of domains where both the SOA paradigm and standard software are of relevance. Here SOA capabilities of products from different vendors can be evaluated within a proposed maturity framework. After pre-requisites and dependencies between distributed components are determined, a high-level architecture can be developed. On the basis of use cases and integration patterns this high level architecture can be refined and verified. Besides methods and related artifacts, we present current adoption issues for standard software packages in service-oriented contexts.