Lesson 3: Scheduling and 4D Simulation

Lesson Overview

Project managers can create a 4D simulation of the planned construction process by linking elements in the composite model to a timeline of project tasks. 4D simulations can have many construction process planning applications; for example, validating the planned sequence are construction operations and identifying any time-based clashes.

Creating a 4D Simulation

By linking timelines of project tasks to model elements, we can create a complete 4D simulation of the construction process from the demolition phase through owner move-in. This simulation can be used to inform critical planning decisions about construction methods, resource allocation, activity sequencing, site space utilization, and so on.

The Navisworks® Manage TimeLiner tool enables project teams to:

  • Manually enter information about project tasks.
  • Import project schedules from a wide variety of project planning tools.
  • Link elements in the composite model with tasks in the schedule.
  • Simulate the schedule and see the effects on the model, including planned versus actual schedules.
  • Export images and animations based on the results of the simulation.

TimeLiner automatically updates the simulation if the model or schedule changes and offers many options for creating customized simulations to support the needs of the project team.

Before linking the composite model to schedule tasks, it is helpful to group model elements and create selection and search sets that facilitate easy mapping; the importance of this point will be demonstrated in the tutorials. 

Identifying Time-Based Clashes

For complicated projects where the site space is constrained, project managers must carefully plan the sequence of operations to make sure that the demolition, permanent construction, and temporary construction activities can occur without creating conflicts. The vast number of moving parts and equipment involved in a construction project makes time-based clash testing incredibly valuable to project managers in their continuing effort to coordinate the trades, materials, and equipment that must coexist in the limited space available.

The ability to forecast and anticipate problems before they occur is essential for effective project management. When the cost of schedule delays or construction rework because of errors is considered, it is clear that project managers need to carefully plan and orchestrate construction operations down to the last detail, both in space and time.

Construction planning models can be created and integrated with the composite project model to consider the impact of temporary items, such as work packages, formwork, cranes, installations, and so on. The locations of these temporary items can be modeled and linked to the project timeline, so that their appearance and removal at particular project locations over specific periods of time can be verified and checked for potential time-based clashes.

By combining the functionality of the Autodesk® Navisworks® Manage TimeLiner and Clash Detective tools, project teams can perform time-based clash checks on the project and continue with this automated checking throughout the project lifetime.

Objectives

After completing this lesson, students will be able to:

  • Define selection and search sets to easily map model elements to the scheduled construction tasks.
  • Assess the best method for mapping model elements to schedule tasks—either manually or by defining mapping rules.
  • Identify problems in construction sequencing through 4D simulation.
  • Understand the various methods available for saving and sharing a timeline simulation.
  • Identify time-based clashes that temporary construction materials.

 

Key Terms

Key Term Definition
Tasks Tag Activities that appear in the project schedule. These activities can include construction, demolition, or temporary operations.
4D Simulation A simulation of a construction process that maps model elements to schedule tasks, adding the fourth dimension of time to a 3D model.
Time-based Clash A clash occurring when two static model elements occupy the same space at a specific time in the project schedule.
Soft Clash A clash occurring when two moving objects collide.
Time-based Soft Clash A clash occurring when the appearance or disappearance of static objects obstructs the movement of animated objects on the site.

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