Introduction to
4D Planning
What is a 4D Model?
A 4D model is the addition of a time element to a 3D model. The combination of the engineering 3D model and the project schedule provides a visual representation of the path of construction (PoC), enabling engagement, collaboration and decision making ahead of the construction activities commencing.
Benefits of 4D Construction Support
The 4D model represents a real-time view of the proposed execution schedule, allowing the project to visualise, validate and optimise the schedule. The use of 4D construction support provides the following benefits to the planning and execution of a construction project:
• Analyse the impact of design changes on the project.
• Identify risk and issues before they happen, leading to a reduction in re-work.
• Improved construction site planning and co-ordination leading to efficient execution of the project.
• Safer construction sites and identification of SIMOPS (simultaneous operations).
• Conflict prevention and resolution.
• Lean scheduling.
• Align construction with resource and material availability.
• Monitoring actual vs planned progress, helping to identify potential issues and reduce claims.
Typical constraints on a construction project
A significant number of major projects experience schedule delays and cost overruns, which can be down to:
• The project scope is not defined properly.
• Inability to accurately estimate time and effort for the project.
• Insufficient detailing of project plans.
• Failure to identify potential risks ahead of time.
• Not using formal project management methodologies and strategies
• Not creating a robust communication channel between engineering, construction teams and stakeholders
• Failure to track additional scope and management of change.
All the points above can be addressed by the project developing a 4D model early in the engineering and construction process.
Over 70% of major infrastructure construction projects now utilise 4D modelling technology to significantly improve construction delivery and safety, for example, London Crossrail, HS2 rail link, Sellafield, Battersea Power Station conversion.