A representation scheme for digital product service system definitions.

The growing trend for delivering physical products to customers as parts of product service systems (PSS) is creating a need for a new generation of Computer Aided Design (CAD) system to support the design of PSS: so-called "PSS-CAD". Key research issues in the development of such systems include building understanding of the kinds of applications that designers of PSS might need and the establishment of well-founded representation schemes to underpin and support communication between PSS-CAD systems. Recent literature includes numerous descriptions of integrated PSS development processes, PSS-CAD tools to support these processes and early meta-models to provide information support. This paper complements this work by proposing a representation scheme that is a key prerequisite to achieving the interoperability between PSS-CAD systems which would be necessary to support the deployment of integrated PSS development processes in industry. The representation scheme, a form of meta-model, draws on learning from the product definition community that emerged in the 1970s in response to a need for interoperability between the different shape-based CAD systems that were being developed at the time. The initial focus on shape representation has developed to digital product definitions that define the design of a product coupled with meta-data recording details of processes by which the design was created and, more recently, supported through-life. Similarly, PSS-related information includes both PSS definitions, to support the lifecycles of physical products and associated services, and meta-data needed to support the management of PSS development processes. This paper focuses on information requirements for the definition of service elements of PSS and relationships with product elements and service actors. These requirements are derived from earlier work on the use of service blueprinting for the visualisation and mapping of service activities to deliver different types of service contract. Key information requirements addressed include the need to represent service process flow and breakdown structures, relationships between service and product elements, substitution relationships, and service variants. A representation scheme is proposed and demonstrated through application to a PSS case study. The representation scheme is built on a generic information architecture that has already been applied to problems of product definition; as such there is an underlying compatibility that offers real promise in the future realisation of integrated PSS development processes