In grown IT infrastructures for Product Lifecycle Management (PLM), applications are mostly interconnected using point-to-point interfaces. This leads to complex and unmanageable infrastructures. A continuous and efficient integration is a key requirement for successful PLM implementations. The Service Oriented Architecture (SOA) is a prevalent solution to efficiently integrate legacy applications and systems into business processes. Its possibility for loose coupling of services enables the replacement of point-to-point interfaces, this way reducing the complexity of managing and maintaining the IT infrastructure. This article introduces a SOA-based solution to the integration of all PLM phases. We employ an Enterprise Service Bus (ESB) as service-based integration and communication infrastructure and introduce three exemplary scenarios to illustrate the benefits of using an ESB as compared to alternative PLM infrastructures. Furthermore, we describe a service hierarchy that extends PLM functionality with value-added services by mapping business processes to data integration services.