Quantifying the Unknown

What is Risk Modelling & Management?

Risk modelling and management is the discipline of identifying, quantifying, and actively managing the uncertainties that affect infrastructure project outcomes. Every construction project operates in an environment of inherent uncertainty: ground conditions may differ from investigations, material prices fluctuate, weather disrupts programmes, design changes emerge, and countless other factors can drive costs above estimates and schedules beyond targets.

Effective risk management goes far beyond maintaining a risk register. It requires quantitative analysis that models the combined effect of project uncertainties using statistical techniques, most notably Monte Carlo simulation. This probabilistic approach replaces single-point estimates and arbitrary percentage-based contingencies with data-driven analysis that reveals the full range of possible project outcomes and the likelihood of achieving budget and schedule targets.

At Cenex, our risk modelling services are delivered by professionals who combine deep expertise in probabilistic analysis with practical experience delivering major infrastructure projects across Queensland. We use industry-leading tools including @Risk and Primavera Risk Analysis to build models that reflect the genuine risk profile of each project. Our analysis aligns with ISO 31000, AACE International recommended practices, and the TMR Project Cost Estimating Manual (PCEM) requirements for risk and contingency analysis.

Whether you need a comprehensive quantitative risk assessment for a business case submission, contingency validation for a funding application, schedule risk analysis for programme assurance, or ongoing risk monitoring throughout delivery, Cenex provides the analytical rigour and practical insight that infrastructure projects demand. Our integrated approach connects risk modelling with cost estimating and planning and scheduling to deliver a complete, consistent view of project uncertainty.

Make Better Decisions

Why Risk Modelling Matters

Quantitative risk analysis transforms uncertainty from a vague concern into measurable, manageable parameters. Projects with rigorous risk modelling consistently achieve better cost and schedule outcomes than those relying on intuition or arbitrary contingencies.

Defensible Contingencies

Replace arbitrary percentage-based contingencies with data-driven, risk-justified calculations that reflect the specific risk profile of your project. Quantified contingencies withstand scrutiny from funding bodies, auditors, and project governance boards because they are based on transparent, repeatable analysis rather than subjective judgement.

Realistic Timelines

Understand probabilistic completion dates at various confidence levels (P50, P80, P90) to set realistic schedule expectations and identify schedule contingency requirements. Schedule risk assessment reveals the activities and risks that drive programme uncertainty, enabling targeted management of schedule-critical issues.

Informed Investment Decisions

Make investment and funding decisions based on a full understanding of risk exposure. Know the probability of achieving budget and schedule targets before committing resources, enabling better capital allocation across project portfolios and more confident stakeholder communication about project cost certainty.

Focused Risk Mitigation

Sensitivity analysis using tornado diagrams identifies the individual risks with the greatest impact on project outcomes, enabling focused mitigation efforts where they will deliver the most value. Rather than spreading limited management attention across all risks equally, quantitative analysis directs effort to the risks that genuinely matter.

Stakeholder Confidence

Demonstrate rigorous, transparent risk analysis to stakeholders, project boards, and funding bodies. Probabilistic analysis builds confidence by showing that cost and schedule estimates have been developed with a clear understanding of uncertainty, and that contingencies are proportionate to the genuine risk exposure of the project.

Proactive Risk Management

Ongoing risk monitoring and model updates keep risk analysis current as project circumstances evolve. As risks are realised, mitigated, or retired, the model is updated to reflect the current risk profile, enabling proactive management decisions based on the latest understanding of project uncertainty rather than outdated assumptions.

Key Decision Points

When You Need Risk Modelling

Quantitative risk assessment delivers value at every stage of the project lifecycle, but is most critical at the decision points where significant commitments are being made based on cost and schedule forecasts.

Business Case & Funding Approval

During the business case phase, quantitative risk assessment informs funding decisions by quantifying the range of possible project costs and the contingency required to achieve target confidence levels. TMR's Project Cost Estimating Manual (PCEM) requires quantitative risk analysis as part of the estimate development process for significant infrastructure investments. A rigorous QRA at this stage establishes realistic budget expectations and prevents the optimism bias that frequently leads to cost overruns.

Design Development & Pre-Tender

As design progresses and project definition improves, the risk model is refined to reflect reduced uncertainty in some areas while capturing newly identified risks in others. Pre-tender risk assessment establishes realistic budget expectations for procurement and provides the basis for evaluating tender responses against probabilistic benchmarks.

During Construction Delivery

Throughout construction, the risk model is updated to reflect the current state of the project as risks are realised, mitigated, or retired. Ongoing risk monitoring provides current contingency forecasts and identifies emerging risks that require management attention, enabling proactive rather than reactive project governance.

Common Triggers for Risk Modelling

  • Business case or funding application requiring quantified cost contingency
  • TMR or government projects requiring PCEM-compliant risk and contingency analysis
  • Schedule risk assessment needed to validate programme achievability
  • Project with significant geotechnical, environmental, or market uncertainty
  • Independent validation of existing contingency allocations
  • Portfolio-level risk analysis for capital programmes with multiple projects
  • Risk workshop facilitation for stakeholder alignment on project risks
How We Deliver

Our Risk Modelling Methodology

Cenex follows a structured, five-phase risk management methodology that ensures comprehensive identification, rigorous quantification, and practical management of project risks.

1

Risk Identification & Workshop

We facilitate structured risk identification workshops with key project stakeholders to systematically identify risks across all categories: technical, commercial, environmental, regulatory, market, and delivery. Our facilitation methodology ensures comprehensive coverage and draws on the collective expertise of the project team.

2

Qualitative Assessment & Prioritisation

Identified risks are assessed qualitatively using consistent likelihood and consequence scales to establish a prioritised risk register. This initial assessment guides the focus of quantitative analysis and ensures management attention is directed to the most significant risks.

3

Quantitative Modelling

We build probabilistic models using three-point estimates and appropriate probability distributions for uncertain variables. Base estimate items are assigned range estimates reflecting estimating uncertainty, while discrete risk events are modelled with probability of occurrence and impact distributions. The model captures correlations between related risk items.

4

Monte Carlo Simulation & Analysis

We run Monte Carlo simulations with thousands of iterations to produce probabilistic cost and schedule outcomes. Results include S-curve probability distributions, confidence level tables (P50, P80, P90), and sensitivity analysis via tornado diagrams to identify the risks with greatest impact on project outcomes.

5

Reporting, Mitigation & Monitoring

We deliver comprehensive risk analysis reports with clear recommendations for contingency allocation and risk mitigation strategies. We provide ongoing risk monitoring and model updates as the project progresses, ensuring analysis remains current and continues to inform project governance decisions throughout delivery.

Why Cenex for Risk Modelling

Cenex brings a unique combination of quantitative analytical capability and practical infrastructure delivery experience to every risk modelling engagement. Our team does not just run simulations; we understand the construction risks being modelled because we have encountered them firsthand on major infrastructure projects across Queensland.

We are CE1 pre-qualified with the Department of Transport and Main Roads (TMR), the highest level of cost estimating pre-qualification, which reflects our deep understanding of the PCEM risk and contingency framework. Our team holds RPEQ certification and brings over $16 billion in total project value delivered across roads, bridges, rail, water, and energy infrastructure. This practical experience ensures our risk models capture real-world uncertainties that purely theoretical analysis may overlook.

Comprehensive Capabilities

Our Risk Modelling & Management Services

From risk identification workshops through to Monte Carlo simulation and ongoing risk monitoring, Cenex provides the full spectrum of risk management services that infrastructure projects require.

Risk Identification Workshops

Facilitated risk identification workshops that systematically identify project risks across all categories using structured techniques. Our experienced facilitators draw on diverse stakeholder perspectives to ensure comprehensive coverage, producing a prioritised risk register that forms the foundation for quantitative analysis and ongoing risk management throughout the project lifecycle.

Quantitative Risk Assessment (QRA)

Comprehensive probabilistic modelling of project cost and schedule using three-point estimates, probability distributions, and Monte Carlo simulation. Our QRA models capture both base estimate uncertainty (range estimates for individual cost items) and discrete risk events (probability of occurrence multiplied by impact), providing a complete picture of project uncertainty that informs contingency allocation and management decisions.

Monte Carlo Simulation

Running thousands of simulation iterations using @Risk and Primavera Risk Analysis to produce probabilistic cost and schedule outcomes. Our simulations generate S-curve probability distributions, confidence level tables, and statistical summaries that clearly communicate the range of possible outcomes and the likelihood of achieving specific budget and programme targets.

Cost Contingency Analysis

Calculation of appropriate contingency levels based on quantified risk exposure and organisational risk appetite. We determine defensible P50, P80, and P90 contingency values that replace arbitrary percentage-based allowances with data-driven calculations tied to the specific risk profile of each project. Our contingency analysis complies with TMR PCEM requirements and AACE International recommended practices.

Sensitivity Analysis

Identification of the individual risks and uncertainties with the greatest impact on project outcomes using tornado diagrams and contribution analysis. Sensitivity analysis reveals which risks drive contingency requirements, enabling project teams to focus mitigation efforts and management attention on the uncertainties that genuinely influence project success rather than spreading resources thinly across all identified risks.

Schedule Risk Assessment

Probabilistic analysis of project programmes to determine the likelihood of achieving target completion dates. Integrated with Primavera P6 schedules via Primavera Risk Analysis, our schedule risk assessment models activity duration uncertainty and discrete schedule risk events to produce probabilistic completion date forecasts. Combined with our planning and scheduling services, this provides a complete view of programme uncertainty.

Mitigation Strategy Development

Development of practical risk treatment strategies including avoidance, mitigation, transfer, and acceptance for identified project risks. We assess the cost-effectiveness of proposed mitigation measures by modelling their impact on the risk profile, enabling project teams to invest in mitigation measures that deliver genuine value rather than implementing costly treatments for low-impact risks.

Ongoing Risk Monitoring

Regular risk review and model updates as the project progresses, maintaining current analysis that reflects evolving circumstances. As risks are realised, mitigated, or retired, the model is updated to provide current contingency forecasts and identify emerging risks. Ongoing monitoring ensures risk analysis remains a living management tool rather than a point-in-time document that quickly becomes outdated.

Industry-Leading Capabilities

Tools & Standards

Cenex maintains proficiency across industry-leading risk analysis tools and aligns our methodology with internationally recognised standards and frameworks.

@Risk
Palisade/Lumivero @Risk for advanced Monte Carlo simulation integrated with Excel-based cost models, enabling detailed cost risk analysis and financial modelling
Primavera Risk
Oracle Primavera Risk Analysis for integrated schedule risk assessment directly linked to Primavera P6 programmes for combined cost-schedule risk simulation
ISO 31000
Risk management aligned with ISO 31000 international standard for consistent, recognised risk management practices across all project engagements
AACE / PCEM
Analysis aligned with AACE International recommended practices and TMR's Project Cost Estimating Manual (PCEM) requirements for risk and contingency
Trinity
Cenex's proprietary Trinity platform for integrated cost-risk analysis, connecting detailed cost models with probabilistic risk assessment
Common Questions

Frequently Asked Questions

Answers to common questions about risk modelling, Monte Carlo simulation, and how quantitative risk assessment benefits infrastructure projects.

What is quantitative risk assessment for infrastructure projects?

Quantitative risk assessment (QRA) is the process of numerically modelling the potential impact of identified project risks on cost and schedule outcomes. Unlike qualitative assessment, which ranks risks using likelihood and consequence ratings, QRA assigns probability distributions to uncertain variables and uses statistical techniques such as Monte Carlo simulation to calculate the combined effect of all risks. The output is a probability distribution showing the range of possible project outcomes, enabling project owners to understand the likelihood of achieving budget and schedule targets at various confidence levels (P50, P80, P90).

How does Monte Carlo simulation work in risk modelling?

Monte Carlo simulation is a statistical technique that models uncertainty by running thousands of iterations of a project cost or schedule model, each time randomly sampling values from the probability distributions assigned to uncertain variables. The combined results of all iterations produce a probability distribution (S-curve) showing the likelihood of the total project cost or completion date falling at any given value. This enables informed decision-making about budgets, contingencies, and schedule targets based on quantified probabilities rather than single-point estimates.

What is the difference between P50, P80, and P90 confidence levels?

P50, P80, and P90 refer to percentile values from a probabilistic analysis. P50 means there is a 50% probability that the actual outcome will be at or below this value (the median). P80 means 80% probability, and P90 means 90% probability. P50 is commonly used as the expected project cost, P80 is often adopted for project budgets as it provides reasonable confidence without excessive conservatism, and P90 may be used for funding approvals or where consequences of exceeding budget are severe. The appropriate confidence level depends on organisational risk appetite.

When should a quantitative risk assessment be performed?

Quantitative risk assessment should be performed at key decision points throughout the project lifecycle. During the business case phase, QRA informs funding decisions. At detailed design, QRA refines contingency estimates. Pre-tender, QRA establishes realistic budget expectations. During construction, QRA is updated to reflect current risk exposure. The Department of Transport and Main Roads (TMR) in Queensland requires quantitative risk assessment as part of its PCEM framework for significant infrastructure investments.

How is contingency calculated using risk modelling?

Contingency is calculated as the difference between the base estimate and the target confidence level from the Monte Carlo simulation. For example, if the base estimate is $50 million and the P80 value is $58 million, the recommended contingency at P80 is $8 million. This replaces arbitrary percentage-based contingencies with a defensible, data-driven calculation reflecting the project's specific risk profile. Sensitivity analysis then identifies which risks contribute most to contingency, guiding mitigation efforts to reduce contingency through active risk management.

What tools does Cenex use for risk modelling?

Cenex uses industry-leading tools including @Risk (by Palisade/Lumivero) for cost risk modelling integrated with Excel, and Oracle Primavera Risk Analysis for schedule risk assessment integrated with Primavera P6. We also use our proprietary Trinity platform for integrated cost-risk analysis. Our framework aligns with ISO 31000 and AACE International recommended practices. The choice of tool depends on project requirements, client preferences, and whether the analysis focuses on cost risk, schedule risk, or integrated cost-schedule risk modelling.

Need Risk Modelling for Your Infrastructure Project?

Our experienced risk analysts are ready to quantify your project uncertainty, validate contingency allocations, and provide the probabilistic analysis that informed investment decisions require. From Monte Carlo simulation to ongoing risk monitoring, we deliver the risk modelling expertise that Queensland infrastructure projects demand. Get in touch to discuss your requirements.