Sustainability in software engineering: A systematic literature review

Background: Supporting sustainability in software engineering is becoming an active area of research. We want to contribute the first Systematic Literature Review(SLR) in this field to aid researchers who are motivated to contribute to that topic by providing a body of knowledge as starting point, because we know from own experience, this search can be tedious and time consuming. Aim: We aim to provide an overview of different aspects of sustainability in software engineering research with regard to research activity, investigated topics, identified limitations, proposed approaches, used methods, available studies, and considered domains. Method: The applied method is a SLR in five reliable and commonly-used databases according to the (quasi-standard) protocol by Kitchenham et al. [1]. We assessed the 100 first results of each database ordered by relevance with respect to the search query. Results: Of 500 classified publications, we regard 96 as relevant for our research questions. We sketch a taxonomy of their topics and domains, and provide lists of used methods and proposed approaches. Most of the excluded publications were ruled out because of an unfitting usage of terms within the search query. Conclusions: Currently, there is little research coverage on the different aspects of sustainability in software engineering while other disciplines are already more active. Future work includes extending the study by reviewing a higher number of publications, including dedicated journal and workshop searches, and snowballing. I. MOTIVATION AND BACKGROUND Sustainability is currently an omni-present term in calls for research proposals and conference sessions (ICSE, CAiSE, RE, etc.). However, in literature, there is no overview of the current state of the art in supporting sustainability in software engineering research and practice. Consequently, researchers who are motivated to contribute to that topic (like the first author [2]) have to invest much time in finding a basic body of knowledge through literature research of many unrelated leads. This paper reports on our systematic literature review with the objective of retrieving a solid basis of knowledge1 on the support of sustainability in software engineering. The full protocol is available online as technical report [4]. 1One of the common motivators for SLRs named by Zhang and Babar in [3, Tab.I]. A. Definition of Sustainability To clarify our research objective, we define our understanding of sustainability and what we mean by sustainability and how we want to apply it to software engineering. The most cited definition of sustainable development [5] is to “meet the needs of the present without compromising the ability of future generations to satisfy their own needs.” According to [5], sustainable development needs to satisfy the requirements of the three dimensions of society, economy, and environment. A fourth dimension, human sustainability, is less present in the public discussion. According to [6], it should be included, as it is the basis for the other dimensions. All four dimensions of sustainability are further detailed on in our SLR protocol [4]. B. Sustainability Aspects in Software Engineering Sustainability aspects can be brought to bear both during the development and use of software systems. We distinguish four aspects of sustainability in SE (orthogonal to the dimensions introduced in Sec. I-A). The development process viewpoint includes: • Development process aspect: Sustainability in the initial system development process (with responsible use of ecological, human, and financial resources). This aspect focusses on the initial conceptual and constructional development and we distinguish it from the late phase of actual system production for reasons of analysis. • Maintenance process aspect: Sustainability of the software system during its maintenance period until replacement by a new system (with continuous monitoring of quality, knowledge management). The product viewpoint encompasses the aspects of sustainability during production and usage: • System production aspect: Sustainability of the software system as product with respect to its use of resources for production (using green IT principles and sustainably produced hardware components). The actual system production happens after most of the initial development process and considers, inter alia, mass production aspects, logistics and factory organization issues. • System usage aspect: Sustainability in the usage processes in the application domain triggered by the software system as product (responsible in impact on environment, using green business processes). We expect these aspects to have different scales of impact, growing from small to large in the order presented above, so that the system usage aspect potentially has the biggest impact (and, therefore, improvement potential). However, this is also dependent of the system under analysis. For our SLR, we are looking for all four aspects of sustainability in software engineering. The aspects imply different levels of abstraction and varied granularity, but nevertheless we are interested in the state of research for each of them. C. A Body of Knowledge for Sustainability in SE Our research aim for the next years is to support the development of ICT systems for environmental sustainability (ICT4ES) with an adequate software engineering approach that integrates the knowledge of related disciplines that are concerned with sustainability. For that we need to build up on existing knowledge is SE as well as disciplines that have been related closer to sustainability, for example, environmental informatics. This research aim requires accumulating a body of knowledge for various reasons: justifying the basis for future research, learning as much as possible from other domains related to the topic, and providing a basis for other researchers as well as students who consider learning about and contributing to this area. One commonly accepted research method for accumulating a body of knowledge is a study in form of a systematic literature review [3]. D. Research Questions The overall research objective of the study is to find out what the current state of the art in supporting sustainability in software engineering research and practice is. This is further detailed in the following research questions: RQ1 How much activity was there in the last 20 years?2 RQ2 What research topics are being addressed? RQ3 What are the limitations of current research? RQ4 How is sustainability support performed? RQ5 Which methods are in use? RQ6 Are there case studies available? RQ7 Which domains are already considered?