Generating, evaluating and visualizing construction schedules with CAD tools

TLDR

Component‑based CAD models are widely used in AEC, yet construction planning is often overlooked because time is not integrated, forcing planners to abstract building components into schedule models; while commercial 4D tools exist, they lack analysis, easy generation, manipulation, and realistic visualizations. The study aims to identify gaps in current 4D CAD tools, outline requirements for construction planning support, and present a new 4D+x tool that more realistically models construction. We develop a 4D‑CAD system that links 3D building models with schedule models via associative relationships, producing 4D+x models that enable realistic construction process representation.

Abstract

Collaborative AEC technologies centering around component-based CAD models support architectural and structural perspectives. The construction perspective is often neglected because an important dimension for construction–time–is missing. Construction planners are forced to abstract CAD model building components into schedule models representing time. 4D-CAD (3D-CAD+time) removes this abstraction by linking a 3D building model and schedule model through associative relationships. Adding time to 3D-CAD models extends the use of CAD tools from the design phase to the construction phase. Although commercial 4D tools exist that allow planners to build 4D models and create graphic simulations of the construction process, these tools lack features to support analysis of these models, easy generation and manipulation of such models, and realistic visualizations of the construction process. This paper discusses these shortcomings, highlights requirements for CAD tools to support construction planning tasks, and describes our efforts to develop 4D tools that generate 4D+x models that more realistically represent the construction process.