Constructing Green Software Services: From Service Models to Cloud-Based Architecture

In recent years, green software research is gaining momentum from the acute need for sustainable development as well as the far-reaching effect of ICT to our society. “[Green and] Sustainable Software is software, whose direct and indirect negative impacts on economy, society, human beings, and environment that result from development, deployment, and usage of the software are minimal and/or which have a positive effect on sustainable development” [4]. Based on this definition, green software research is growing in two directions. The first direction looks into the runtime energy consumption of software [15] and its engineering pro-aspects of our society and investigates how software can be used to improve the sustainability of a broader range of business, social, and individual activities [5]. This chapter is focused on the research and development in the second direction—to leverage software to solve sustainability problems on a wider scope. The emergence of cloud computing and Internet of Things (IoT) makes software services further reach out to the physical world at a larger scale. Many existing business operations are being improved with respect to scalability and manageability through automation. Such new developments have strong implications to green software research since sustainability can be improved by applying software services based on these new computing paradigms. This view prompts us to rethink the delivery models and service scope of green software: when green software is delivered as online services, or green software services (GSS), a broader range of business, governments, and individual processes can more easily employ the services to reduce their energy consumption. Furthermore, more flexible business relationships can be established between different stakeholders so that the financial