Due to an increasingly competitive environment and the thriving of more ambitious and complex projects, construction managers have been forced to enhance their project management skills to achieve successful results in terms of cost, quality and time. In order to do so, the implementation of innovative scheduling tools that allow project management teams to evaluate multiple scenarios or risks at the planning stage of a project becomes a crucial factor to foresee and mitigate conflict situations. Moreover, the quest for and use of such tools should not be limited to the planning stage, since there is also a need to identify and mitigate issues during the execution phase and maximize the efficiency of the Project Manager’s decision-making process by providing a clearer panorama.
This tendency requires more focused scheduling tools that need to be chosen depending on the type of project at hand. The critical path method (CPM) is the most utilized scheduling tool in the construction industry worldwide. Nevertheless, there are types of projects in which CPM’s usefulness decreases because it becomes complex and difficult to use and understand, becoming impractical and losing its core purpose. Alternative scheduling tools designed for specific types of projects can prove to be more suitable and useful than CPM solutions. Here is where linear scheduling takes importance.
Traditionally, linear scheduling is used as a visual representation of a construction schedule for projects that follow a linear production path with a large number of repetitive activities such as: highways, bridges, pipelines, dams, high-rise buildings, rail construction projects, among others. The linear schedule displays work sequence information similar to that on a CPM schedule or Gantt chart in a way that is easier and more intuitive to interpret. This paper explores the potential for broadening the applications of this tool for critical decision-making analyses by displaying and correlating information that would be less apparent otherwise.
A case study illustrating the use of forensic linear scheduling as a data visualization tool to quantify delay is offered as an example of the technique was applied in the Borinquen Dam 1E construction, a 5 million cubic meter (6.54 million cubic yards) earthfill dam constructed by the Panama Canal Authority as part of the USD 5.2 billion Panama Canal Expansion Program. The case study demonstrates how as-built information can be introduced into a linear schedule format to perform forensic claim analysis and support. Variables such as daily rain precipitation, geological conditions at the dam’s foundation and unattended available areas to work are displayed and clearly identified in a single linear schedule to graphically depict the project’s as-built condition based on daily reports. By using a contractually binding source of information such as the project’s daily reports, an objective representation of the project facts is obtained by this method, which allows to potentially resolve disputes.
In addition, this paper also proposes an alternative method for identifying and managing the scheduling aspect of geotechnical risk using a linear-scheduling-based tool that was also implemented for the construction of the Panama Canal’s Borinquen Dam 1E. The alternative method is compared to the traditional format that involves expert interpretation of subsurface information in order to communicate the risk properly. A model was developed using linear scheduling and incorporating stochastic simulations in a way that the impact of geotechnical risk is assessed as a function of the expected underground conditions, which can be displayed directly in the linear schedule. The analysis finds that the method effectively provides a better understanding of the risk management effort and introduces a way to incorporate variables into the assessment that otherwise would not be available for quick reference, such as the interpretation of the geological profile of the project site. By doing so, a connection is made between technical aspects (such as the geotechnical interpretation) and the project management effort.
This paper’s contribution to the body of knowledge is to provide innovative applications of the linear scheduling method to graphically depict data that is not readily available when using traditional means, increasing the effectiveness of decision-making and improving the way construction projects are managed.