PCEM Section 4

The PCEM Cost Estimating Process

A comprehensive 15-step framework for developing accurate, defensible cost estimates for Queensland infrastructure projects

Overview of the Estimating Process

The Project Cost Estimating Manual (PCEM) defines a systematic 15-step process for developing cost estimates. This standardised approach ensures consistency, accuracy, and defensibility across all Queensland infrastructure projects, regardless of size or complexity.

Following this structured process helps estimators:

Capture all project costs comprehensively
Apply appropriate estimating methods based on available information
Manage uncertainty through risk assessment and contingency
Validate estimates through peer review and reality checks
Document assumptions and methodologies for transparency
Counteract optimism bias inherent in project planning

The process is designed to be scalable - simple projects may require less detail at certain steps, while complex mega-projects demand rigorous application of every element. Regardless of project scale, all 15 steps must be considered and documented.

Key Principle: The estimating process is iterative, not linear. As new information becomes available throughout the project lifecycle, estimates must be revisited and refined. Early estimates are based on limited information and require larger contingencies; later estimates benefit from detailed design and market engagement.

The 15 Steps of PCEM Cost Estimating

Each step in the PCEM process builds upon the previous one, creating a comprehensive foundation for accurate cost estimation. The following sections detail each step and its critical components.

Establish Project Scope

The foundation of any estimate is a clear understanding of what is to be delivered. This step involves defining project boundaries, deliverables, constraints, and exclusions. The estimator must identify what is included in the estimate and what is not, documenting any assumptions about scope interpretation.

Key activities: Review project brief, identify stakeholder requirements, define geographic and temporal boundaries, clarify performance specifications, document scope assumptions and exclusions.

Collect Available Project Information

Gather all relevant documentation that will inform the estimate. This includes design drawings, specifications, geotechnical reports, environmental assessments, traffic studies, utility plans, and any previous estimates or feasibility studies. The quality and completeness of information directly impacts estimate accuracy.

Key activities: Collect design documentation, review previous estimates, obtain site investigation reports, gather stakeholder requirements, identify design gaps, document information quality and completeness.

Become Familiar with the Project Site

Direct site knowledge is invaluable for identifying cost drivers and constraints that may not be apparent from documentation alone. Site visits reveal access challenges, existing conditions, environmental sensitivities, utility conflicts, and constructability issues that significantly impact costs.

Key activities: Conduct site inspections, assess site access and logistics, identify existing infrastructure, evaluate environmental constraints, understand local conditions, photograph key features, document site-specific cost impacts.

Collate Estimating Information

Organize and structure all information gathered in previous steps into a format suitable for estimating. This includes developing quantity take-offs from drawings, extracting unit rates from historical data, identifying applicable standards and specifications, and preparing the estimating framework aligned with the Work Breakdown Structure (WBS).

Key activities: Develop quantity take-offs, organize information by WBS, identify applicable rates and benchmarks, prepare estimating templates, document measurement methods and assumptions.

Determine Work Item Types

Classify each cost element according to how it will be estimated and managed. Work items fall into four categories: fixed quantity items (known scope and quantity), measured items (quantity estimated from design), provisional items (allowances for anticipated but undefined work), and lump sum items (complex activities priced as a package).

Key activities: Classify each WBS element by item type, define measurement units, establish basis for provisional allowances, identify lump sum packages, document classification rationale.

Understand Historical Data

Leverage Queensland's SmartCost database and other historical project data to inform rate development. Historical data provides benchmarks for similar work, but must be adjusted for project-specific conditions, location factors, market conditions, and scope differences. Understanding the context of historical data is as important as the data itself.

Key activities: Access SmartCost database, identify comparable projects, extract relevant unit rates, adjust for location and timing, validate data applicability, document data sources and adjustments.

Develop Base Estimate

Calculate the base construction cost using appropriate estimating methods. Four primary methods are available: global estimates (top-down, high-level rates), unit rate estimates (quantities multiplied by unit rates), first principles estimates (detailed resource-based buildup), and hybrid approaches combining multiple methods. Method selection depends on design maturity and required accuracy.

Key activities: Select appropriate estimating method(s), calculate quantities, apply unit rates or develop resource buildups, price preliminaries and indirects, document all calculations and assumptions, prepare detailed estimate breakdown.

Undertake Reality Checks

Validate the base estimate against independent benchmarks and sanity checks. Compare the estimate to similar completed projects, industry benchmarks, parametric checks, and alternative calculation methods. Significant variances require investigation and explanation. This step catches errors and identifies items requiring refinement.

Key activities: Compare to similar projects, perform parametric checks, validate key rates, review quantity reasonableness, investigate anomalies, document reality check results and adjustments.

Assess Project Risks

Systematically identify and quantify risks that could impact project costs. This involves conducting risk workshops with project stakeholders, identifying threats and opportunities, assessing likelihood and consequence, and quantifying potential cost impacts. Risk assessment feeds directly into contingency determination in the next step.

Key activities: Conduct risk identification workshops, assess likelihood and impact, quantify cost implications, develop risk register, identify mitigation strategies, document risk assessment methodology.

Determine Level of Contingency

Calculate appropriate contingency to account for estimate uncertainty and identified risks. Two approaches are available: deterministic (applying percentage-based allowances to estimate elements) or probabilistic (using Monte Carlo simulation for quantitative risk analysis). Business case estimates require both P50 and P90 confidence levels. Contingency must be justified, not arbitrary.

Key activities: Select contingency method, apply deterministic percentages or run probabilistic analysis, calculate P50 and P90 values where required, document contingency rationale, establish draw-down protocols.

Determine Cashflow and Escalation

Project the timing of expenditure and apply escalation to account for cost changes over time. This involves developing a cashflow profile based on the construction program, applying escalation rates from Queensland Treasury's economic parameters, and calculating the outturn cost (today's dollars plus escalation). Cashflow impacts both funding requirements and escalation calculations.

Key activities: Develop construction program, create cashflow profile, obtain current escalation rates, calculate real and nominal costs, present estimate in outturn dollars, document escalation assumptions.

Presentation of Costs

Organize and present the estimate in formats required by stakeholders and governance processes. Estimates must be presented in outturn dollars (including escalation), clearly distinguish between Capital Expenditure (CapEx) and Operational Expenditure (OpEx), and align with the PCEM Work Breakdown Structure for consistency. Multiple presentation formats may be required for different audiences.

Key activities: Format estimate to PCEM WBS, separate CapEx and OpEx, prepare executive summary, develop detailed backup, create presentation materials, ensure consistency across all estimate views.

Estimate Validation

Subject the estimate to independent peer review to verify accuracy, completeness, and methodology. All estimates require peer review by qualified cost estimators not involved in the estimate development. Projects exceeding $25 million also require concurrence review by Cost Estimating 1 (CE1) pre-qualified estimators. Validation findings must be addressed and documented.

Key activities: Engage independent peer reviewers, facilitate concurrence review for projects over $25M, respond to review findings, document validation process, incorporate recommendations, obtain reviewer sign-off.

Estimate Approvals

Obtain formal approvals from appropriate governance levels based on project value and phase. Approval requirements vary by agency and project phase, but typically include project director approval, executive endorsement, and potentially ministerial or cabinet approval for major projects. The estimate and supporting documentation must be submitted through defined approval channels.

Key activities: Prepare approval submission, compile supporting documentation, present to approval authorities, address questions and concerns, obtain formal sign-off, distribute approved estimate to stakeholders.

Document and Capture in 3PCM

Record the final estimate and all supporting information in the Program and Project Cost Management (3PCM) system and project files. Comprehensive documentation ensures traceability, supports future estimate updates, enables lessons learned analysis, and provides an audit trail. Documentation includes the estimate itself, assumptions, methodologies, data sources, risk assessments, peer review reports, and approval records.

Key activities: Upload estimate to 3PCM system, document all assumptions and exclusions, compile backup calculations, archive source data, prepare estimate narrative, ensure documentation completeness and accessibility for future reference.

Understanding and Counteracting Optimism Bias

Optimism bias is the demonstrated systematic tendency to underestimate costs, timescales, and risks while overestimating benefits in project planning. This cognitive bias affects all projects and all estimators, regardless of experience or intention.

What is Optimism Bias?

Research from the UK Treasury and other international bodies has conclusively shown that project cost estimates are typically optimistic, with actual costs exceeding initial estimates by significant margins. This is not due to poor estimating practice or deliberate manipulation, but rather an inherent human cognitive bias towards optimism when planning future activities.

Common manifestations of optimism bias in cost estimating include:

Underestimating complexity: Assuming construction will proceed smoothly without delays or difficulties
Overlooking risks: Failing to adequately account for known risks or identify emerging risks
Base rate neglect: Ignoring historical performance data in favor of project-specific optimism
Planning fallacy: Focusing on best-case scenarios rather than typical outcomes
Scope creep blindness: Not anticipating scope growth that typically occurs during design development
Strategic misrepresentation: Consciously or unconsciously presenting low estimates to secure approval

PCEM Measures to Counteract Optimism Bias

The PCEM framework incorporates several specific measures designed to counteract optimism bias and produce more realistic estimates:

1. Mandatory Historical Data Reference

Step 6 requires estimators to reference Queensland's SmartCost database of completed project costs. This grounds estimates in actual historical performance rather than optimistic projections.

2. Structured Risk Assessment

Step 9 mandates systematic risk identification and quantification. This forces explicit consideration of what could go wrong, counteracting the natural tendency to assume everything will proceed according to plan.

3. P50/P90 Confidence Levels

Business case estimates must present both P50 (50% confidence) and P90 (90% confidence) values. This explicitly acknowledges uncertainty and ensures governance decisions are made with realistic expectations.

4. Independent Peer Review

Step 13 requires independent validation of all estimates. Fresh eyes from qualified estimators provide objective assessment and challenge optimistic assumptions. Concurrence review for projects over $25M adds additional scrutiny.

5. Reality Checks and Benchmarking

Step 8 mandates comparison against independent benchmarks and alternative calculation methods. This catches estimates that are significantly optimistic compared to industry norms or similar completed projects.

6. Documented Assumptions and Exclusions

Throughout the process, estimators must document all assumptions, exclusions, and areas of uncertainty. This transparency makes optimistic assumptions visible and challengeable.

Practical Application

Effective estimators actively question their own optimism throughout the process:

When developing quantities, ask "What have I missed?" rather than assuming completeness
When selecting rates, favor actual historical data over theoretical calculations
When assessing duration, reference actual completed projects rather than ideal scenarios
When identifying risks, challenge the team to think of unlikely but possible events
When setting contingency, resist pressure to minimize in favor of realistic uncertainty allowances

Key Insight: "The greatest enemy of a good cost estimate is the optimism of the estimator. The PCEM process is deliberately designed to counteract this bias through structured analysis, historical grounding, risk quantification, and independent review. Following the process rigorously produces estimates that are credible, defensible, and realistic."

How Cenex Applies the PCEM Process

As a CE1 pre-qualified cost estimator, Cenex has developed rigorous internal procedures that align with and enhance the PCEM 15-step process. Our approach ensures every estimate meets PCEM requirements while adding value through experienced application.

Our Process Enhancements

Structured Information Gathering

We maintain comprehensive checklists for Steps 1-4 to ensure no critical information is overlooked:

Project kick-off meetings with all key stakeholders
Detailed design review workshops to identify gaps and inconsistencies
Systematic site visits with documented photo records
Formal RFIs to designers when documentation is incomplete

Hybrid Estimating Methodology

For Step 7, we employ hybrid estimating combining multiple methods based on design maturity:

First principles: Critical elements and complex work
Unit rates: Standard elements with Queensland benchmarks
Global rates: Early estimates with limited design information

Comprehensive Reality Checking

Our Step 8 reality checks go beyond simple benchmarking:

Multi-level checks: WBS Level 1, 2, and critical Level 3 elements
Parametric analysis: Project-specific unit rates vs industry benchmarks
Trend analysis: Cost escalation tracking against market conditions
Peer challenge: Internal senior review before external submission

Structured Risk Workshops

Step 9 risk assessment is critical to estimate credibility:

Pre-workshop risk identification using checklists and historical reviews
Facilitated workshops with project team and client representatives
Structured assessment using calibrated likelihood/consequence scales
Post-workshop quantification using probabilistic techniques

Advanced Contingency Analysis

Step 10 techniques appropriate to project scale and complexity:

Deterministic: Applied at WBS element level with justification
Monte Carlo: For business case estimates requiring P50/P90
Sensitivity analysis: Identifying cost drivers and testing assumptions
Scenario planning: Alternative outcomes based on decision points

Clear Communication

Steps 12-14 focus on presentation and approvals:

Executive summaries: One-page overviews for decision-makers
Detailed breakdowns: WBS-structured with full traceability
Visual presentation: Charts, graphs, and infographics
Comparison reports: Clear explanation of changes from previous estimates

CE1 Pre-Qualified Expertise

Cenex is pre-qualified under Queensland's Cost Estimating 1 (CE1) panel, demonstrating our capability to deliver estimates for the most complex and valuable infrastructure projects. Our estimators hold relevant qualifications, have extensive Queensland project experience, and undergo continuous professional development to maintain currency with PCEM requirements and industry best practice.

Quality Assurance

Every Cenex estimate undergoes internal quality assurance before client delivery:

Peer review by senior estimators not involved in estimate development
Verification of calculations and data sources
Compliance check against PCEM requirements
Review of assumptions and documentation completeness
Director-level sign-off before submission

This rigorous process ensures that estimates delivered to clients are accurate, defensible, and ready for governance approval processes.

Need PCEM-Compliant Cost Estimates?

Cenex delivers CE1 pre-qualified, PCEM-compliant cost estimates for Queensland infrastructure projects.