Schedule Risk Assessment

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Location:  PMKI > Project Controls and Scheduling > Schedule Risk Assessment. 
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Every estimate about a future outcome is uncertain! This subject looks at the effect of uncertainty on schedule predictions and the tools and techniques available to manage the consequences of uncertainty and improve the accuracy of projected completion dates.

Topics included in Schedule Risk Assessment:

- Schedule Risk Overview
- Risk Assessment and Analysis
- Schedule Risk Tools
- Useful External Web-links & Resources.

Other related sections of the PMKI:

- Risk Management  
- Risk management & Decision Support Software.


Schedule Risk Overview

Every estimate included is a schedule has a degree of risk (ie, uncertainty that matters) associated with the estimate. It is impossible to predict the future with complete certainty - recognizing and managing this risk leads to far better project outcomes than attempting to avoid the risk through contracts or simply ignoring the issue. For more on managing risk, visit our advanced risk management page.

Art: Predicting project completion. The use of Earned Schedule and the 'P-Factor in determining a realistic completion date are defined.

Blg: Predicting Completion. The requirement to finish a 'project' on time with associated penalties for late completion hs been around for 3000 years. The question asked in this post is when did predictive tools start to emerge to give the contractor some insight into the consequences of current performance rates?



S1//S5 Maturity FrameworkSchedule Risk Assessment and Analysis

A well developed, realistic schedule reduces risk. The stages in developing this are:

  1. A comprehensive schedule that accurately reflects the way the project's work will be undertaken. Discussed in Scheduling Good Practice
  2. A technically sound schedule that conforms to industry standards. Discussed in Schedule Quality Assessment 
  3. Proper consideration and allowance made in the schedule for uncertainty (risk events) and variability
  4. The completed schedule reviewed and optimized to offer the best overall outcome
  5. Team and customer/client validation and buy-in  - the schedule will only be useful if it is used!

PP: Why Critical Path Scheduling (CPM) is Wildly Optimistic. The factors that drive CPM towards an optimistic initial assessment including psychological biases, single point estimates and limitations of the CPM modelling process are defined and quantified.

WP: Understanding PERT. PERT is the oldest and arguable the least effective / least accurate way to model uncertainty. This paper traces the origins of PERT and the reasons for its limitations.

SCRAM: The Schedule Compliance Risk Assessment Methodology. SCRAM is an approach for identifying risks to compliance with the program schedule, it is the result of a collaborative effort between Adrian Pitman from the Australian Department of Defence, Angela Tuffley of RedBay Consulting in Australia, and Betsy Clark and Brad Clark of Software Metrics Inc. in the United States. SCRAM focuses on schedule feasibility and root causes for slippage. It makes no judgment about whether or not a project is technically feasible. SCRAM can be used:

  • By organizations to construct a schedule that maximizes the likelihood of schedule compliance.
  • To ensure common risks are addressed before the project schedule is baselined at the commencement of a project.
  • To monitor project status, performed either ad hoc or to support appropriate milestone reviews
  • To evaluate challenged projects, to assess the likelihood of schedule compliance, root cause of schedule slippage and recommend remediation of project issues

For more information and free resources see:



Schedule Risk Tools

Schedule risk tools model uncertainty based on statistical probability:

Art: Standard Deviation for Project Managers. The concepts behind Standard Deviation and how it is used.

Art: Predicting Future Project Outcomes - The power of uncertainty. Monte Carlo, Latin Hypercube and Sampling.

Two commercial tools that apply these concepts are:

Acumen RiskDeltek Acumen Risk - Accurately predict completion and understand the impact of high-risk activities in terms of dollars and days. Acumen Risk is an integrated cost/schedule risk analysis tool combining true cost and schedule risk analysis against a native project plan together with identified risk events from a project risk register. It was the first truly integrated and easy-to-use cost/schedule risk analysis and risk register software that helps you effectively account for and proactively reduce project risk exposure. Acumen Risk’s Uncertainty Factor is a simple-to-use sliding scale that project teams can relate to, to develop a truly integrated means of linking schedule risk to cost risk so that you can determine the impact of schedule delays on your project cost estimate.

See more at:


Barbecana’s Full Monte

Full Monte Tornado Chart

Full Monte is schedule risk analysis software that integrates seamlessly with Microsoft Project 2007 through to 2016. Full Monte for Oracle Primavera P6 is a standalone application working directly against the P6 database, so requires no import or export. Full Monte utilizes the Monte Carlo simulation method, and is fast and easy-to-use. Some of the features include:

  • Probability distributions for task durations, resource cost rates, and calendars.
  • Correlations between durations, cost rates.
  • Autocorrelation and seasonality in calendars.
  • Full results for every task.
  • Sophisticated sensitivity analysis.
  • User-defined reports.

See more at:



Useful External Web-links & Resources

SCRAM - Schedule Compliance Risk Assessment Methodology home page: 

RedBay Consulting Pty Ltd (developer of SCRAM):


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