Bentley Updates 4D Oldie but Goodie

construction.com May 21, 2001

By Harry Goldstein

One of the first serious attempts at creating a dynamic 4D CAD model was undertaken by Buddy Cleveland's team at Bechtel Corp., San Francisco, Calif., in the late 1980s and was aimed at plant construction. Later, Cleveland's team was spun off by Bechtel as Jacobus Technology, which was later bought by Bentley Systems Inc., Exton, Pa., and provided the base technology for Bentley's current Schedule Simulator product.

Allan Nixon, Product Manager, Viecon Integration, explains that the Schedule Simulator is entirely independent of Bentley's MicroStation and can import models from AutoCAD, Intergraph and others, as well as Microstation Triforma, and link them to applications like Primavera Project Planner (P3) or Microsoft Project. Users can then navigate the completed model, replay the project schedule, and step through that proposed schedule.

Nixon says that while the Schedule Simulator originated in the plant market, "a number of customers use it in the building industry as well," though he couldn't say how many.

The product is currently being merged with Bentley's Dynamic Animator, which will allow users to apply motion to objects. The most recent version of Schedule Simulator released in March 2000 is the first step in integrating the Dynamic Animator and the Simulator. The newly dynamic simulator will let users do things like real-motion crane positioning and live crash detection.

The customer base for Schedule Simulator is broad, with engineering consultants who do design-build using the Simulator to optimize schedule and design for constructability. Owner-operators who do their own small scale in-house design work use the program to ensure that their planned schedule is feasible. They also do what-if scenarios to confirm their ideas, see what's on the critical path of the project and come up with contingency plans if a delivery is late or there is a weather delay.

The Bentley tool requires quite a bit of up-front preparation. Integrating schedule and model is a process based on rules that need to be determined before the 4D model is created. Once in place, users "can apply those rules to link components in the model to the schedule, so as the project goes on, your model is changing and your schedule is changing," Nixon explains.

Nixon says that while the Schedule Simulator is "a useful tool, it goes beyond that." He sees the Simulator as part of the foundation for an enterprise system that will integrate with facilities, operations and management systems, ultimately extending the life of the 4D model and making it increase in worth throughout the lifecycle of the building.

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