SI can be defined as innovation in service products, referring to new or improved intangible goods supplied through service activities. SI can also be defined as innovation in service processes, referring to the production of products in new or improved ways which can take place in both service and manufacturing firms. SI is sometimes used to mean "innovation in services", which refers to any sort of innovation within service firms (Miles, 2010). For example, den hertog (2010) defines SI as innovations emerging from several dimensions of an organisational service system. This broad definition of SI has proved to be problematic. It has caused some confusion in studying different types of innovation issues in a service context. The confusion between SI and BMI in existing literature is a typical example. It could be argued that the attempt to stretch the concept of SI to contain any sort of innovation in service sectors may result in this concept having almost no meaning. It may be better to narrow down the concept by exclusively focusing on innovation in service products so as to deepen our understanding of this type of SI in comparison to other innovation phenomena such as technology innovation and management innovation. In addition, previous studies have suggested that innovation often takes place in a systemic manner. In other words, a successful innovation often requires the development of a set of complementary innovations (Fagerberg, 2005; Teece, 1986). Based on the above discussion, we redefine SI as innovation in core service products (the dominant benefit or satisfaction that customers expect from a service they buys) which may need the support of a set of complementary innovations, particularly innovation in core processes (the minimum individual tasks to be accomplished to provide a service to customers). We believe that this definition is clear enough to solve the conceptual confusion between SI and other types of innovations without necessarily denying many widely accepted concepts in innovation studies.