• he global economy is a large service system in need of innovation to grow (see Table 1 ). Service systems are value-creation networks composed of people, technology, and organizations (see the accompanying figure). Interventions taken to transform state and coproduce value constitute services. For instance, in IT outsourcing, a service provider operates the computing infrastructure for a service client. The provider augments the client's capabilities, taking on responsibility for monthly service-level agreements and year-over-year productivity improvements. The formal representation and modeling of service systems is nascent, largely because of the complexity of modeling people, their knowledge, activities, and intentions. Service system complexity is a function of the number and variety of people, technologies, and organizations linked in the value creation networks, ranging in scale from professional reputation systems of a single kind of knowledge worker or profession [1] , to work systems composed of multiple types of knowledge workers [4] , to enterprise systems (for example, businesses) [87] , to industrial systems [9] , to national systems [51, 102] , and ultimately to the Formal representation and measurement of work in service systems is a grand challenge for the services economy (see Table 2 ). We do not yet know how best to measure work and knowledge value reconfiguration in service systems. To illustrate the complexity of formally modeling services systems, consider four examples: education, IT service delivery centers, call centers, and patents. Example 1. Education as a Service System. Education is fundamental in any society. The educational system transforms young people with general literacy skills into entry-level professionals (knowledge workers). After the dot-com bubble burst and outsourcing of IT jobs to India became a common headline in newspapers, many universities in the U.S. and Canada witnessed sharp drops in enrollment for computer science. The directors of computer science departments, who had seen increasing demand for several decades, were now facing three problems: faculty complained of fewer, less able students entering their classrooms; industry complained of a poorer match between the needs of business and the computer science graduates being produced; and faculty recruiting and morale were declining on some campuses. How might a service scientist approach the problem of creating service innovations and improving the educational service system? First, the service scientist might identify the stakeholders and interview them to learn of the boundaries of the service system and of any problems and opportunities that the stakeholders see. Second, a service scientist might create a formal model of the service system, including a table of all stakeholder interactions, what technologies and organizations mediate those interactions, and who owns or does not own the perceived problems and opportunities. To be clear, the challenge lies not simply in formally modeling the technology or organizational interactions, but in modeling the people and their roles as knowledge workers in the system. Traditional modeling assumes people are either (a) like machines or other resources, (b) different in that they can be modeled as a set of skills that change with experience, or (c) different in that they form relationships and social networks to improve productivity. The third step for a service scientist might be to extrapolate the year-over-year evolution of the system and the hour-by-hour activities of stakeholders. A service scientist might then envision new service systems that could be put in place to solve each problem. Sometimes the needed service systems are well known, and financial investment is all that is needed-new stakeholders are added. Or perhaps leaders can encourage existing stakeholders to multitask on new activities-requiring that existing stakeholders do more to enhance their professional The definition of services in terms of relationships and actions among service provider, service client, and service target, based on [38].
REF defined the complexity of service systems as "a function of the number and variety of people, technologies, and organizations linked together in the value creation networks".
Service systems, service scientists, SSME, and innovation
CACM
Computer Science