COOPS: Construction object-oriented process simulation system.

Abstract

Simulation of construction operations provides detailed process information, such as resource utilization and idleness, operation bottlenecks, production rates, and cost before the work actually begins. Even though construction-specific simulation systems are the easiest to use in actual practice, they still have several limitations, such as lack of resource tracking, lack of direct graphical modeling, the complexity of modeling different resource units, and indirect resource availability control. COOPS, a new simulation system designed by the author, addresses some of these limitations. COOPS is a general-purpose discrete-event simulation system that provides an integrated environment for construction process modeling. COOPS simulation models are represented as graphical networks of nodes and links, similar to those used by CYCLONE. All modeling elements, including resources, activities, queues, links, consolidations, routers, and flags, are implemented as objects that have extensive behavioral functionality. Real-world resources can be modeled as resource objects in the system. Activity objects are used to represent tasks to be performed in a construction process. Queue objects are used to model a storage place for resources. Link objects define the precedence relationship between queues, activities, consolidations, and routers. The simulation network itself is developed interactively on the screen by using graphical editing tools similar to those used in vector-based drawing programs. COOPS allows for modeling generic construction resources and tracking the utilization of particular resources. Special resource objects can be created in the model and routed dynamically to collect additional data. COOPS also provides direct mechanisms for controlling resource availability using the concept of calendars which define the working and non-working cycles of resources. Detailed statistics are collected and kept inside the objects as the simulation proceeds. New modeling and resource objects can be created easily, and the existing objects can readily be enhanced to provide additional functionality as needed.