National Grid UK, the electricity transmission system owner for England and Wales and the system operator for all of Great Britain, uses @RISK’s probabilistic modeling techniques to measure network restoration performance in a variety of simulated failure scenarios. In other words, if the system, or part of it, somehow breaks down, the people at the utility want to know what, and how long, it will take to get it working again, and what the challenges will be along the way.
@RISK can be used in conjunction with MS Project and Excel to model the schedule and cost risks inherent in large, complex projects. This example demonstrates the use of @RISK to build a complete model of the construction of a new commercial venue. The model includes uncertainty in task times, a Risk Register for calculating contingencies, and a link to real-time cash flows in an NPV calculation model.
@RISK probability distributions have been assigned to the durations of several tasks in the schedule, some with a distribution and others using Risk Categories. The uncertain task times are assumed to be uncorrelated.
A Risk Register lists three possible risk events that could impact the project schedule and costs. By using the RiskProjectAddDelay function, these risks introduce schedule delays and associated costs. Specifically, this function allows the model to generate new tasks dynamically, depending on whether the risks occur or not. Changes are reflected at run time only, so it is necessary to run a simulation to see the impact and results of the Risk Register.
The example also contains a model of cash flows that leads to the NPV of the project. In particular, the project costs create a Timescaled Data report. This collects the total cumulative costs during a simulation. After a simulation, you can see the total cumulative costs for the project as they grow over time.
The other reports generated are the NPV and the Contingency for the Risk Register, at different confidence levels. Finally, the cash flow also includes a Revenue Adjustment calculation that takes the portion of the year in which Sales are initiated and applies a discount to the predicted annual revenue.