A construction project holds manifold of activities occurring at the same time in one physical area. These activities involve people, materials, and equipment along with variables of time and space. The scheduling of these activities, more often than not, is accessible independently in a one-dimensional timeline sheet. So how can this 1D timeline sheet provide a real-time status update, or identify unforeseen material shortage, workspace clashes, equipment failure or onsite accident? It can’t. At least not on its own.
4D BIM refers to 3D visualization model of a construction project that includes the construction scheduling and sequencing. 4D BIM adds scheduling data of the project even before the construction started. This enables teams to analyze events sequentially using project information and visualization. Going through the sequencing at the initial stage, even before the real site is dug, allows assessment of various possibilities and thus improve project planning and risk management. And the ability to visualize the structure at each stage as it gets built will lead to a reduction of waste in money, and obviously in time.
However, the excitement doesn’t end there. What if the time of an activity can be visualized with the exact location of where the activity is expected to take place? Construction industry suffers from delays all the time. One of the main reasons why such delays occur is due to multiple activities being planned within the same location, resulting in queuing of activities. Location-based scheduling ensures activities are planned in relation to the locations. Although the method has been around for a long time, it is being picked up by construction industry of late, thanks to the digitization agenda.
Location-based scheduling requires a highly-detailed location break down, which is a challenging process especially in large and complex projects. By integrating it with BIM, however, locations of building elements can be easily identified and any overlaps can be rectified. This is why the value of location-based scheduling can only be maximized through 4D BIM. The spatial insight that 4D BIM can offer exceeds those of 2D and 3D.
Location-based 4D BIM, as the name suggests, is rather complex and demanding. Decisions on location decomposition need to be made and agreed on by many different stakeholders. Building elements need to be designed in pieces following the real-time construction process. And of course, the most demanding prerequisite is the initial cost to set up a 4D-planning system. The software, capacity building, and implementation cost could be expensive, although it is a one-off cost, and companies are expected to gain back the investment in the final result.
The focus and purpose of location-based 4D BIM is to enrich the planning and scheduling process in a construction project. At the same time, communications and stakeholder participation can also be improved, resulting in a robust delivery approach that can be understood, validated and reliably implemented by the project delivery team.
Project owners stand to gain the most out of this approach:
- Reduction in mistakes in a construction site, most of the time due to lack of information.
- Time-saving – remedial work will be minimized, extra site visits due to incidents can be avoided, and unnecessary ‘extra meetings’ to discuss schedule confusion is no longer required.
- Cost saving – since there’s no more ‘floating cost’ in the margin for assumed delays, congestion or contractors’ overtime.
BIM enables increasingly more advanced, and more intelligent designs. Constructing that design is also increasingly more complex. Therefore, a single integrated model that clearly projects the ‘when’ and ‘where’ of every construction activity can determine the right project delivery approach and execution. Location-based 4D BIM is a tool to achieve just that.