## 7 Discussion  
Because using BIM for FM is relatively new to the AECO industry, the characterization of an FM-enabled BIM process is still unconsolidated. Moreover, as observed in practice, design and construction teams are often involved in FM-enabled BIM processes without fully understanding their required contributions. Although a considerable number of studies on BIM for FM have been conducted in the past years, few studies have documented the  
Figure 16: Average level of perceived influence of each identified challenge for the successful implementation of BIM for FM. whole process of development and delivery of asset information using BIM following pre-established information requirements and its implications in real large-scale projects [10; 11]. Therefore, empirical knowledge such as the common BIM data requirements for O&M, current BIM data delivery and presentation methods, use of new technologies, and hypothetical BIM-O&M use cases are still required as a foundation for the development of more powerful and generally applicable standards, guidelines and BIM-based solutions for facility O&M [2]. This gap was addressed by documenting the processes being adopted in the local industry through case studies, which captured knowledge such as information requirements, main activities, information workflow, scope of each stakeholder, and tools. Eight fundamental steps were identified across three different projects: a. Definition of the information requirements (BIM requirements), b. Model development observing BIM requirements (creation of digital assets in BIM), c. Validation of the asset information in BIM (compliance with BIM requirements), d. Model updates based on design changes during construction, e. Data extraction from design models to an external database (creation of an asset registry), f. Association of asset information from the construction phase with respective digital assets in the external database, g. Validation of the asset information in the external database, and h. Asset information upload into FM systems. Different approaches towards the integration of BIM and FM systems have been studied. Ref. [11] categorized four of them: (1) using BIM model as an FM data repository [8; 21; 36; 51; 87]; (2) entering the required information to BIM models and transferring it to CMMS or computer-aided facility management (CAFM) systems [44; 45; 64; 65]; (3) storing data from FM systems in a database and linking it with a BIM model to visualize and query it in BIM [27; 30; 33]; and (4) using BIM-FM platforms to integrate BIM models with FM systems [88]. This study demonstrates a mixed approach in which the required information is provided collaboratively by different stakeholders at different stages of the project using a BIM-FM platform as an external database, where all the geometric and non-geometric asset information produced during design and construction is gathered and organized per asset, and then transferred into the CMMS. The approach discussed in this study differs from the first approach because no information related to FM activities is brought into the BIM models. Instead, the information flow through BIM is unidirectional, meaning that BIM data is used to feed other systems, but data from other systems are not brought back into the models for further analysis. This helps avoid the limitations related to the capacities of BIM authoring tools and large file sizes. Although similar, the approach in this study differs from the second approach because a BIM-FM platform is employed and because not all the required information for FM is entered in BIM. Instead, different pieces of the required information are provided by different stakeholders at different stages of the project. While the information required from the design phase is generated in the models, the information required from the construction phase is fed directly into the BIM-FM platform. One of the limitations previously described in method two is the lacking capacity to visualize geometric information in the CMMS.