Service-Oriented Architecture is a paradigm for modeling and enacting business processes that promotes improved flexibility and monitorability through the composition of loosely-coupled Web services. However, such process-centric composition, with focus on invoking Web services to reach a stated goal, still does not provide the desired flexibility. Web services implementations are typically locked into the business logic of the business processes that they implement. Additionally, monitoring such Web services compositions becomes cumbersome especially for business analysts and managers who are not IT experts. To address these issues, this paper presents a unified process- and data-centric approach with focus on Web services as a driving element to the changes affecting both processes and data. In this approach a business process is modeled as a collection of interacting (business) artifacts, each of which behaves as per a predefined state transition system called Artifact Life-Cycle (ALC). An ALC is enriched with contextual details, which permits business process execution monitoring. Throughout this paper, a realistic running example in the purchase order domain is used for illustration purposes.