Improving the utility and value of CAD software for decision-making and design of structural frames

Three-dimensional modeling and visualization software is increasingly being used by building designers to represent structural frames and communicate design information upstream to their clients and downstream to suppliers/manufacturers. Although design processes and design management have been explored extensively per se, the upstream, heuristic decision-making stages of design in relation to 3D software appear to be underresearched. This is understandable because the human side of the process is complex and therefore less straightforward to map. Nevertheless, decisions made early in the project, such as the choice of structural frame, are critical to the project’s overall success. Studies of current practice indicate that such decisions tend to be based on heuristic decision-making processes rooted in subjectivity and qualitative reasoning. This paper reports the development of an objective, transparent and systematic selection process that operates effectively within a 3D modeling environment. An innovative framework for simultaneously comparing the performance of a range of structural options against agreed criteria was developed, using the two measures, Importance (I) and Performance (P), which can be used to calculate a Performance Weighted Score (PWS). This framework is a means of assessing ‘soft’ factors, alongside the conventional cost and time parameters now used in 4D modeling. It thus provides a useful example of a methodology for integrating ‘soft’ decision making in an otherwise ‘hard’ software environment.