Most project owners or key decision makers would agree that having the opportunity to not only recognize schedule risks and uncertainties, but also prepare and proactively plan for them ahead of time is an ideal proposition, especially on complex design-build projects. With advanced scheduling methods, this is a sure bet. Design-build contractors using the stochastic modeling technique offer owners the opportunity to recognize and quantify project risks and make proper decisions to meet their overall project objectives with a new level of confidence and control. Here are a few things owners and contractors should consider when using advanced scheduling on their next design-build project.
Shuffling the Traditional Project Schedule Provides a Better Understanding of Costs and Timelines
Traditional critical path method (CPM) project schedules are deterministic meaning that they show one possible way to plan and execute the project. The process starts by first identifying the project work breakdown structure and tasks, planning and sequencing work depending on which activities should come first, and finally developing a logic-based CPM schedule model utilizing a project management software such as Primavera P6. The limitation to deterministic schedules is that the duration of tasks is just a forecast and represents single-point duration estimates. Unknown risks and uncertainties could easily affect the original plan and lead to schedule and cost over-runs.
The stochastic modeling technique shakes up the traditional project schedule by using Monte Carlo simulation to determine and manage schedule and cost variables. Identified risks and uncertainties along with their probability distributions are added to the schedule using a comprehensive risk assessment software such as Primavera Risk Analysis (PRA), with additional data such as three-point duration estimates (Min, Most Likely, Max), inclement weather calendars (using National Oceanic and Atmospheric Administration or NOAA historical data), resource uncertainties, and qualification and quantification of risks from the project’s risk register. Building upon the deterministic schedule created in Primavera P6, the added Monte Carlo simulation conducts random sampling of the identified risks and uncertainties with respect to their probability of occurrence and distributions and a probabilistic model is then produced showing the outcome for both schedule and cost.
Next, the mitigation analysis and scenario planning helps to examine several different outcomes, depending on whether certain things occur, and to choose a proper response strategy to achieve desirable results.
Preparing for the Best Hand Begins Before the Groundbreaking
The best way for owners and contractors to succeed at advanced scheduling is to plan early, align expectations and consider all possible risks and uncertainties including those that are not part of the design-build scope of work, which could influence the delivery of the project. It is prudent that owners fully and clearly define project scope and expected allocation of the project risks and uncertainties along with a well-defined responsibility matrix, within the initial request for proposal. Owners should consider utilizing advanced scheduling and stochastic techniques to properly determine and allocate adequate time and budget contingencies to their projects.
Putting A Stake in a Master Schedule Provides Better Control During Project Execution
Another key component to making advanced scheduling work and maintaining control throughout the project is by incorporating all scope and tasks into one master schedule for all project stakeholders. The master schedule should also assign responsibility to the various stakeholders involved to hold each party accountable for timely execution of their project tasks. Schedule updates for forecasting purposes should also be communicated regularly to ensure that all parties are informed of the project status and aware of upcoming project milestones and deadlines. The master schedule will serve as great leverage to the owner in making sure their objectives are being met.
Owners Can Avoid Playing Roulette with their Project Schedule
Ultimately, the stochastic modeling technique gives the power back to the owner by allowing them to determine the best approach for their design-build project. If schedule is the driver for completing the project, the owner can identify which risks and uncertainties can most likely affect meeting their deadlines and determine the best path forward. Likewise, if cost is a driver, any high-probabilistic outcomes that lead to increased costs can be clearly identified in a stochastic model, giving the owner the opportunity to make alternative decisions better suited to their budgeting needs.