Model-Based Mechanisms for Automated Activity Sequencing

This paper describes model-based mechanisms used in the Construction Method Modeler (CMM) system to automate activity sequencing. CMM is a model-based AI-planner for construction that supports the rapid generation of detailed and realistic construction plans from a computer-interpretable project description (product model). CMM generates multiple plan alternatives for the same project without having to alter the product description or the underlying knowledge base. CMM generates two types of alternatives. (1) Different parts of a project, even if they consist of the same types of components, are planned using different models of construction methods. (2) The whole or parts of the same project are planned to different levels of detail. CMM uses activity-based sequencing agents to automate activity sequencing. They apply and enforce abstracted sequencing knowledge at the individual activity level. In this manner, they can sequence plans whose different parts use different construction methods. Sequencing agents reason about abstracted and prioritized component-based relationships to sequence activities elaborated to varying levels of detail. CMM sequences activities that act on components that are represented at different levels of detail. With these model-based sequencing mechanisms, project planners can maintain fully sequenced and interlinked construction plans at multiple levels of detail throughout the life of a project.