## 2 Background
The integration of BIM into the IT environment enables transitioning the current'react to event' practice to 'predict the event' practice [26]. The integration of BIM into cloud computing allows project stakeholders to collaborate in real-time from different locations to enhance decision-making and ensure project deliverability [5]. The IoT, together with BIM, is able to maximize productivity [27], enhance the information flow during a project life cycle [28], optimize energy efficiency [29], and improve security and safety [30; 31], as well as the planning, managing, and monitoring of resources [31]. The number of research publications covering topics related to Industry 4.0 and construction have grown tremendously. For example, in the Scopus database, for \"Industry 4.0\" OR \"Industrial revolution 4.0\" AND TOPIC \"construction\" OR \"building\" search keywords, the number of publications have increased every year. In year 2015, eight papers were recorded. This increased to 27 papers in 2016, 59 in 2017, 163 in 2018, and the numbers is growing in 2019 with 364 published papers as of May 2019. Of these, 196 papers were conference papers, 105 were journal articles, 10 papers were review papers, and the rest were other types of publications. Most of the papers were published in _Advances in Intelligent Systems and Computing_ (17 papers), _Procedia Manufacturing_ (13 papers), _IFIP Advances in Information and Communication Technology_ (11 papers), and _IOP Conference Series Materials Science and Engineering_ (11 papers). From all the papers found, only three review papers provided significant impact related to Industry 4.0 in construction: \"Understanding the implications of digitization and automation in the context of Industry 4.0: A triangulation approach and elements of a research agenda for the construction industry\" [32], \"Industry 4.0 as an enabler of proximity for construction supply chains: A systematic literature review\" [33], and \"Digital construction: From point solutions to IoT ecosystem\" [26]. These three publications provided an overview of the potential of the industrial revolution in the construction industry in term of practice and supply chain. Much room exists for exploration related to this topic in the construction industry as the pattern and structure in this area of study are still in their infancy and conceptual. A mapping study was used to provide a systematic and objective procedure to identify the pattern and structure of an existing study [34] to discover little evidence likely exists in a broad topic [35] such as construction within Industry 4.0. Our underlying research question was to determine how extensive the studies related to the topic are, with a secondary question to discuss the methodological approaches used in the studies to understand the movement of the topic. The objectives of this systematic review were (1) to identify, assess, and analyze the published studies to understand the prevalent patterns and structures in existing work related to Industry 4.0; (2) to identify the gaps in this topic; and (3) to propose a framework that links the current research topics to future research directions. With these objectives, we identified the most relevant authors, the topics that have already been covered, and, finally, potential future research directions. This overview will help researchers understand the current state of the construction industry within the Industry 4.0 era and reduce the digital gap throughout a project life-cycle. This paper is structured as follows. Section 3 explains the selection of the information resources and information mapping. The next section provides reports and discussion of the results in some fields, knowledge area, authors, and keywords. Finally, Section 5 provides our conclusions and suggestions for future research.