Optimized Scheduling of Linear Projects

This paper presents a model, designed to optimize scheduling of linear projects. The model employs a two-state-variable, N-stage, dynamic programming formulation, coupled with a set of heuristic rules. The model is resource-driven, and incorporates both repetitive and nonrepetitive activities in the optimization process to generate practical and near-optimal schedules. The model optimizes either project construction duration, total cost, or their combined impact for what is known as cost-plus-time bidding, also referred to as A1B bidding. The model has a number of interesting and practical features. It supports multiple crews to work simultaneously on any activity, while accounting for: ~1! multiple successors and predecessors with specified lead and lag times; ~2! the impact of transverse obstructions, such as rivers and creeks, on crew assignments and associated time and cost; ~3! the effect of inclement weather and learning curve on crew productivity; and ~4! variations in quantities of work in repetitive activities from one unit to another. The model is implemented in a prototype software that operates in Windows environment. It is developed utilizing object-oriented programming, and provides for automated data entry. Several graphical and tabular output reports can be generated. An example project, drawn from the literature, is analyzed to demonstrate the features of the developed model. DOI: 10.1061/~ASCE!0733-9364~2003!129:6~664! CE Database subject headings: Scheduling; Models; Construction industry; Dynamic programming; Optimization.