The Cost Management Unchecklist

Few things undermine confidence in a major project faster than a budget surprise.

Yet as infrastructure programmes become larger, more complex and more heavily scrutinised, agencies can be asked to make significant funding commitments before all the facts are known.

The challenge is not simply estimating cost, it is making informed investment decisions in an environment where uncertainty is unavoidable.

In this article, we’re exploring 5 of the most common budgeting misconceptions we see across government infrastructure and capital programmes, and how agencies can improve cost confidence, strengthen business cases and make more defensible funding decisions.

1. Estimates inform decisions. Budgets reflect decisions.

One of the most important distinctions in project governance is the difference between an estimate and a budget.

An estimate provides evidence. A budget reflects a funding decision.

Consider a new facility with an estimated delivery cost of $100 million. While the estimate reflects the project's expected cost based on available information, the approved budget may be set at $110 million to provide additional funding certainty. Equally, budget constraints may result in only $90 million being allocated, requiring scope reductions or alternative delivery strategies. In both cases, the estimate informs the decision, but the budget reflects the choices made by project sponsors and funding authorities.

An estimate seeks to identify:

"What is the most likely cost of delivering the project?"

A budget reflects broader organisational considerations, including:

• Funding constraints
• Risk appetite
• Escalation provisions
• Client costs
• Programme priorities
• Strategic investment objectives

When cost forecasts change, the focus should be on understanding:

1. What assumptions have changed?
2. What risks have emerged?
3. What new information has become available?

An estimator provides value well beyond producing a cost figure. They help decision-makers understand what the project is likely to cost, what could influence that outcome, and how much confidence they can have in the numbers being presented.

And the most successful agencies? They recognise that estimates inform decisions, but budgets are ultimately determined through good governance.

2. Contingency is a protection mechanism, not spare funding

Every major project contains uncertainty. Compliance requirements may change. The soil might be contaminated. There could be procurement challenges. And all this before an unexpected month of rain.

Contingency is the mechanism used to recognise and manage this uncertainty.

It’s not, as is often the misunderstanding, the funding for additional scope or discretionary enhancements.

A good estimator will factor in contingency to address the risks that remain after planning and design activities have been undertaken. They’ll consider things like:

• Ground condition uncertainty
• Utility relocation risks
• Design development changes
• Market pricing fluctuations
• Construction productivity risks

Importantly, removing contingency does not reduce risk exposure. It simply reduces an agency's ability to respond when those risks materialise.

Good cost management treats contingency as an essential risk management tool to support successful delivery.

3. Choosing the cheapest estimator can become the most expensive decision

Government agencies rightly focus on value for money. But when procuring estimating services, there is often a temptation to compare proposals primarily on fee. At first glance, the logic seems sound. If 2 providers can deliver an estimate, why pay more?

Estimating is about much more than just producing a number. It is about providing confidence in the decisions that that number will support.

When budgets are understated, projects can face:

• Additional funding requests
• Delayed approvals
• Business case rework
• Scope reductions
• Procurement challenges
• Erosion of stakeholder confidence

The difference between 2 estimating proposals is usually a fraction of a project's overall budget. The consequences of budget uncertainty, however, can run into millions of dollars and months of delay.

The best estimating advisers do far more than prepare cost reports - they challenge assumptions. They identify gaps in scope. They test delivery strategies, assess risks, consider market conditions and help project teams understand where uncertainty may exist before it becomes a problem.

The question agencies should ask is not:

"Who can provide the estimate at the lowest cost?"

It is:

"Who can provide the greatest confidence in our investment decision?"

Estimating should not be viewed as a procurement commodity. It is a critical part of project assurance, governance and risk management.

4. Quality assumptions matter more than more detail

More detail does not always move an estimate from P50 to P90 and beyond. Detailed estimates are important, but alone they cannot guarantee accuracy.

A quality estimation process will test underlying assumptions like:

• Is scope definition complete and robust?
• Are project requirements set, or are they likely to change?
• What is unknown about this site (and when will we find out)?
• Is the strategy set, or is there room for movement?
• What is the market doing, and what is being forecast?
• What level of confidence do we have in the risk assessment?

A useful question for project sponsors to as cost estimators is not:

"How many line items are included?" It’s: "How robust are the assumptions underpinning the estimate?"

The most effective cost assurance processes focus on testing assumptions, validating scope and understanding risk drivers.

Confidence comes from understanding uncertainty, not ignoring it – and a quality estimation will provide this.

5. What takes estimating from good to great?

When agencies engage estimating advisers, traditional evaluation criteria often include:

• Experience
• Capability
• Fees
• Resources
• Delivery timeframe

But the greatest value comes from the quality of decisions that the estimation supports throughout the project lifecycle.

The highest-performing estimating teams will provide all the above, but they will also help agencies:

• Understand affordability
• Improve business case confidence
• Identify emerging risks early
• Test alternative delivery approaches
• Strengthen funding submissions
• Reduce procurement surprises
• Improve project assurance outcomes

The real measure of success is not whether every cost prediction is exact. It’s whether decision-makers have what they need to make informed, defensible and transparent investment decisions. It is about supporting good governance, public investment stewardship and decision confidence.

The best estimators do not tell project leaders what they want to hear. They tell them what they need to know.

Cost Management at TSA Riley

From project start-up through to tendering and construction, we support informed decisions as projects evolve – balancing market conditions, financial viability, functional and stakeholder requirements, with delivery timeframes.

We’ll help you gain clarity on what’s driving costs and where changes will have the greatest impact, enabling smarter, more informed trade-offs. By connecting cost with scope, time, quality, and carbon, we help you stay in control and make confident decisions.

Find out more: Cost Management | TSA Riley