Business services arguably play a central role in service-based information systems as they would fill in the gap between the technicality of Service-Oriented Architecture and the business processes captured in Enterprise Architecture. Business services have distinctive features that are not typically observed in plain Web services. The representation of business services requires that we view human activity and human-mediated functionality through the lens of computing and systems engineering. We give insights into the modeling of business services and relationships between them. This work sheds light on the analysis, design and reusability of business-aware services that business owners, entrepreneurs and business architects alike would find useful when dealing with their service ecosystem. © 2011 Lam-Son Lê.