4D simulations are often used to show the construction sequence for an entire project, but shorter simulations that focus on a specific period of time are also useful.
- Can you provide examples of how a simulation that focuses on a 1 or 2 week period could be useful for planning?
A short duration 4D simulation is valuable because it zooms in on a more realistic pace of construction. When project teams can visualize just one or two weeks of work, they can better coordinate site logistics, sequencing of trades, and day-to-day resource needs. This tighter window also highlights constraints that don’t always show up in a full project simulation. For example, curing periods of concrete or equipment availability and delivery windows. By narrowing the scope, teams can validate whether their workflow is truly buildable on site and adjust the plan before issues carry over into later phases.
What level of detail should be included in a 4D simulation?
- Should you include all of the elements in the building model?
You only need to include the model elements that meaningfully impact how the project will be built. Major structural frames, main mechanical lines, and any assemblies that dictate workflow or trade coordination are typically sufficient. Excessive detail tends to slow down the simulation without adding value. For example, small interior components like door handles and flooring finishes (finishes in general) don’t need to be included. Similarly, furniture, small MEP components, and overly detailed geometries are unnecessary- existing in other shop drawings or plans elsewhere.
How can the feedback shown in a 4D simulation help you to optimize the project schedule?
- What are the main benefits of linking model elements to the project schedule?
Linking model elements directly to the project schedule allows teams to see the implications of their planning decisions immediately. A 4D simulation acts like a visual check that reveals sequencing overlaps, idle time, or constructability issues that might not be obvious in a gantt chart or with other scheduling methods (CPM?!). When the model shows an unrealistic order of operations or a missed dependency, teams can revise the schedule early. Conversely, the visualization may also show opportunities to run activities concurrently or streamline mobilizations. Because the model and schedule update together, it becomes easier for teams to integrate field updates and maintain a schedule that reflects current site conditions.