Cities are complex ecosystems; they rely on multiple stakeholders and core systems to provide wide-ranging services for citizens and businesses. As such, ecosystem thinking and modeling is crucial to understanding and transforming cities. Existing literature, such as Systems Dynamics and Urban Ecosystems, offers useful insights into the subject, but it has significant limitations in effectiveness, reliability and scope. to address the knowledge gap, a holistic and integrated approach is proposed, drawing upon IBM's proven and emerging methods, notably Component Business Modeling (CBM) and Actionable Business Architecture (ABA). The new approach intends to represent the whole business of city ecosystem, unveil dependencies among constituent parts and facilitate integration from strategy to operations and technologies. Its first outcomes were made available as a strategy and transformation capability in the Smarter Cities portfolio. Further research is planned and its potential contributions to theory and practice are explained. © 2011 IEEE.