Describing Service Systems Robert J. Glushko School of Information, University of California, Berkeley, California Abstract There are many different normative frameworks for describing service systems that take a distinct con- ceptual perspective. They emphasize the physical arrangement or topology, the functions or processes, the chronology of experience, the causality of value creation, the flow of information or people, or other characteristics. These frameworks are deeply embedded in service system research and design practice, but we have not known how useful or natural they are. University students new to service science concepts described a service system they all used—the Bay Area Rapid Transit (BART) system. They identified and categorized the services they encountered or that were involved when they used BART and then created diagrams to depict the system. There was substantial variation in how students described BART in terms of scope, overall number of services, and their granularity. There was also great diversity in the classification of services and in the diagrams or other representations students cre- ated. Since most students had little exposure to normative frameworks for describing service systems, their diagrams were often hybrids of different frameworks. C  2012 Wiley Periodicals, Inc. Keywords: Service system; Service classification; Service description frameworks 1. NORMATIVE FRAMEWORKS FOR SERVICE SYSTEMS The holistic view embodied in the service system con- cept makes it possible to describe person-to-person en- counters, the service offerings of an enterprise, the ser- vices in a city, or even larger components of a national or global service network as service systems. Many dis- ciplines, including design, business management and strategy, operations research, industrial engineering, informatics, and information systems, rely on frame- works that can be used to describe service systems. These frameworks are often normative in that they mandate the constructs that should be used to describe some aspects of a service system, the type of infor- Correspondence to: Robert J. Glushko, University of California, School of Information, 102 South Hall, Berkeley, CA 94720. e-mail: glushko@berkeley.edu Received: 30 August 2011; accepted 2 April 2012 View this article online at wileyonlinelibrary.com/journal/hfm DOI: 10.1002/hfm.20514 mation required to instantiate each construct, and the conventional notations or representations in which to present the system description. The frameworks are often taught in a prescriptive manner, and some are supported by software whose inputs and outputs are highly standardized. The frameworks are not equally applicable to all ser- vice systems because they differ in their organizational scope, the degree to which they capture a conceptual or implementation-neutral model of a possibly hypothet- ical system rather than a more concrete and physical model of an existing one, and the extent to which they embody quantitative data rather than qualitative ob- servations about the actual or predicted operation of the service system. Nevertheless, because they share some conceptual and structural abstractions, more than one framework can often be insightfully applied to the same service system to highlight different aspects or perspectives. In particular, many of the frameworks are dynamic or time based to represent interactions between ser- vice providers and customers that take place over time, Human Factors and Ergonomics in Manufacturing & Service Industries 00 (0) 1–8 (2012) c  2012 Wiley Periodicals, Inc. 1