Updating and Documenting a Schedule Risk Analysis

A schedule risk analysis should be performed on the schedule periodically as the schedule is updated to reflect progress on activity durations and sequences. As the program progresses, risks retire or change in potential severity, and new risks that were previously categorized as “unknown unknowns” may appear. The time between SRA updates will vary according to program length, complexity, risk, and the availability of management resources. A contractor should perform an SRA during the formulation of the performance measurement baseline to provide the basis for contractor schedule reserve at the desired confidence level. Preferably, an SRA is also performed before key decision points throughout the program. An SRA might occur more regularly, for instance, to support annual budget request submissions so that adequate contingency can be included in the budget baseline.

SRAs should also be performed as needed, as when schedule challenges begin to emerge with a contractor and when schedule contingency is consumed at a higher-than-expected rate or is consumed by the materialization of risks not included in the risk register. The risk register should be updated with any new risks identified during risk analysis data collection. An updated SRA is particularly important to support the internal independent assessment process if the program is rebaselined or if significant changes are made to the risk register. Keeping the program schedule current is discussed in Best Practice 9 and rebaselining is discussed in Best Practice 10.

Each update to the SRA should be fully documented to include the risk data, sources of risk data, and techniques used to validate the risk data. In addition, the methodologies used to perform the simulation should be detailed, and outputs such as a prioritized risk list, the likelihood of the program completion date, the activities that most often ended up on the critical path, and the derivation of contingency sufficient for risk mitigation should be documented.