Constantly evolving, the construction industry has an advantage – the advantage of a variety of project processes and associated services at its disposal. The emergence of BIM (Building Information Modelling) on the pre-construction scene itself was a landmark of sorts, and this led to the development of closed BIM. Closed BIM is a process where the same software (sometimes the same version) of a BIM application is utilised by all project stakeholders. Closed BIM represents a bounded design environment, where stakeholders must necessarily work in a singular software suite or platform. In this process, the same BIM software used by one BIM vendor is used by all stakeholders in the project, including different disciplines, to produce, for example, architectural models, MEP models and structural models and provide relevant services, including BIM design and architectural and BIM MEP services.
To more clearly comprehend how closed BIM works, here is an example: The architectural designer drafting the plans and creating the 3D models will use the same BIM software as the design engineer who creates MEP service routes and as the structural consultant who creates steel and concrete structure designs using the same software. The same software will also be used by the project manager to monitor and maintain the build programme and the safety coordinator to provide documentation. No file conversion is required in this method, and it only allows collaboration between participants well versed with certain BIM tools. The advantage in this approach on a project is that it reduces interoperability issues seen in projects where participants work with different software and ultimately improves coordination workflow.
When considering ‘closed’ BIM, the logical query would be: What is ‘open’ BIM?
Unlike closed BIM, open BIM is a process shared by several different software vendors. Open BIM is a concept where associated disciplines maintain translatability, both with the model and the data. Open BIM supports an open workflow, allowing project members to participate regardless of the software tools they use, and the execution of open BIM requires the creation of a common language for widely referenced processes. Executing complex projects with dispersed teams means that design processes can take more time, and this has an overall effect on the project schedule. The different teams at work require updated models and easy access to the models both off and on site. Expensive rework on site could result from extra time spent on multidisciplinary collaboration.
Closed BIM, on the other hand, can improve efficiency and reduce models reviews. When closed BIM connects the whole team, everyone involved in the project has easy access to a single model and project BIM data.
The importance of BIM 3D modelling services is paramount in the stages of design, pre-construction and construction. In this process, there is a distinct possibility that bottlenecks may occur at some point, since several stakeholders from different disciplines have access to the models. These bottlenecks can be minimised to a great degree in a closed BIM environment.
Another advantage of using a closed BIM process is time and money saved on training. For instance, a developer or homebuilding company may have in-house designers, estimators, a project manager and so on. In this case, using a single company-wide application, such as the same version of Revit 2018, with one easy-to-use interface (so different systems need not be learnt or trained on) would save cost and time.
Though open BIM sounds inclusive, it can give rise to challenging interoperability issues. For example, there can be loss of data or parts of models appearing incorrectly between BIM software, which is inefficient, inaccurate and risky. Rates data must be assembled and assigned to drawing objects, which can be disproportionate to the cost and complexity of the project. The closed BIM approach is often preferred, since it minimises interoperability problems.
In closed BIM, multidisciplinary teams can seamlessly share project data. Stakeholders can easily share files. Having a common interface, the need for file conversion or importing/exporting does not exist and subscribers can make selections from a range of wholly integrated modules. In other words, there is 100% compatibility.
Information can be accessed, viewed or modified securely at any time or anywhere, improving communication and decision making in closed BIM. Models can be annotated, and notifications can be communicated easily. Specific views and markups can be accessed from the notifications. Point-to-point tools and object snapping enable the measurement of distances between model objects. The shortest distances between objects are automatically calculated.
A BIM-compatible software tool, such as BIM 360 Glue or Revit 2018, makes BIM accessible to everyone on the team and helps streamline project workflows. So, in a closed BIM environment, where stakeholders use BIM 360 Glue and accurate clash detection tools such as Navisworks, for example, team members can spot and resolve clashes and conflicts more effectively. Additionally, in a cloud-based environment, the latest project models and data can be viewed and modified from any location. Conflicts and concerns along the way can be communicated via notifications. This would prevent expensive rework on site.
Some of the other benefits of closed BIM in coordination workflow are:
Managing Information: Digital elevation, along with laser scans of existing infrastructure, provide detailed and extensive data. In the closed BIM environment, this helps streamline workflows. Also, designers and other stakeholders have access to a large well of data in a model. If, for instance, project stakeholders are working on the same version of Revit 2018, the compatibility between the players in the project means that it is easier to export into Navisworks, and also it is easier for Facilities Management, as it is not necessary to create IFC (Industry Foundation Classes) formatted files first.
Less Rework: A shared model in closed BIM means there is less rework. Annotations in each discipline can be communicated across the board, since all players are on the same software platform. BIM drawing tools are accurate and precise and make use of libraries. Windows and other elements can be updated automatically during the progression of the model.
Controlling Environment: The model-based workflow can be kept focused, since stakeholders with the same software tools are unlikely to alter the process or introduce new elements, even by accident. Loss of data and corruption of files is reduced.
Sharing and Collaboration: Functions are delivered in the cloud, for example Autodesk’s BIM 360 solutions, enabling extensive sharing and collaboration. Tools for each discipline from the same platform allow easy sharing of models and coordination. Review and markup tools ensure that everyone is collaborating on the design and are set for execution on finalization of the concept.
Resolving Conflict: Closed BIM tools help to automatically detect clashes. When models are created early, clashes are found early, and expensive on-site clashes are reduced. Models also help facilitate the perfect fit of off-site elements with on-site elements.
Accessing from Anywhere: Availability of much information and with the capability of the cloud in closed BIM, the model and its details can be accessed from anywhere, on any device.
Closed BIM can also benefit specific professionals involved in the process. Stakeholders in the coordination workflow benefit from closed BIM as follows:
Architects: Closed BIM benefits architects by helping with the seamless execution of the design phase of the project process.
Structural Engineers: Structural engineers can model elements such as steel columns, beams and trusses with efficient collaboration in closed BIM.
Fabricators: As closed BIM reduces conflicts and builds confidence in plans, fabrication appears to be a favourable option. Fabrication with accuracy cuts down on waste and time can be saved by pre-assembly.
MEP Engineers: The closed BIM process helps model elements, such as duct systems and air handlers, as well as electrical switches and outlets.
Construction Managers, General Contractors: With reduction in rework, projects can stay within budget. This can lead to construction managers and general contractors passing on these savings to owners.
Overall, closed BIM improves design workflow in a number of ways for a varied range of project stakeholders, in all areas from architectural design development to 3D BIM coordination and coordinated drawings, leading to faster, more accurate output.
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