E-Services are typically delivered point-to-point. However, the e-service environment creates the opportunity for providing value-added, integrated services, which are delivered by composing existing e-services. In order to enable organizations to pursue this business opportunity we have developed eFlow, a system that supports the specification, enactment, and management of composite e-services, modeled as processes that are enacted by a service process engine. Composite e-services have to cope with a highly dynamic business environment in terms of services and service providers. In addition, the increased competition forces companies to provide customized services to better satisfy the needs of every individual customer. Ideally, service processes should be able to transparently adapt to changes in the environment and to the needs of different customers with minimal or no user intervention. In addition, it should be possible to dynamically modify service process definitions in a simple and effective way to manage cases where user intervention is indeed required. In this paper we show how eFlow achieves these goals.