Not all descriptions of "services" are applicable to "service systems". Here's a useful reference, by the Institute for Manufacturing and IBM.
A service system can be defined as a dynamic configuration of resources (people, technology, organisations and shared information) that creates and delivers value between the provider and the customer through service.
In many cases, a service system is a complex system in that configurations of resources interact in a non-linear way. Primary interactions take place at the interface between the provider and the customer. However, with the advent of ICT, customer-to-customer and supplier-to-supplier interactions have also become prevalent. These complex interactions create a system whose behaviour is difficult to explain and predict. (IfM and IBM, 2008, p. 6)
A range of service systems in the 21st century lists everyday features of modern civilization.
An important -- but often misinterpreted idea -- in service systems is ways in which Creating Interactive Value might be achieved.
Source: IfM, and IBM. 2008. Succeeding through Service Innovation: A Service Perspective for Education, Research, Business and Government. Cambridge, UK: University of Cambridge Institute for Manufacturing. [http://www.ifm.eng.cam.ac.uk/ssme/] .