Project Overview

TAG Advisory serves as the Independent Estimator on the High-Capacity Signalling project, one of Western Australia's most complex and transformational rail infrastructure programmes. This ongoing engagement involves establishing and validating project budgets approved and funded by WA State Treasury for both significant capital investment over the next decade and substantial operating costs through the subsequent maintenance period. The project will modernise Perth's rail network signalling systems, enabling increased service frequency and network capacity to support the city's growth.

Key Challenges

The project presents exceptional technical complexities requiring sophisticated understanding of modern signalling technologies, systems integration and operational transformation. The scale of replacing legacy signalling across the entire metropolitan rail network whilst maintaining daily operations creates unprecedented delivery challenges requiring careful staging and extensive possession planning.

Significant capital and operating costs demand rigorous estimation approaches to ensure Treasury confidence. The extended delivery timeline spanning ten years of capital investment followed by long-term maintenance by the AD Alliance requires robust whole-of-life cost modelling. Market uncertainty for specialised signalling systems, limited global supplier base and evolving technology standards add layers of complexity to cost forecasting.

The integration of new signalling systems with existing rail infrastructure, rolling stock modifications, control centre upgrades and operational process changes creates interdependencies that must be carefully valued and risk assessed.

Methodology and Approach

TAG Advisory implemented a comprehensive independent estimation framework tailored to the project's unique characteristics and extended timeline. As Independent Estimator, the approach ensures complete objectivity whilst maintaining technical rigour across all cost elements.

Key estimation activities include:

• Analysis of technology obsolescence and refresh cycles
• Assessment of systems integration and testing requirements
• Baseline capital cost development for signalling equipment and installation
• Benchmarking against international high-capacity signalling projects
• Evaluation of enabling works and infrastructure modifications
• Inflation and escalation modelling over the extended timeline
• Operating cost modelling for the maintenance period
• Risk quantification for technical, commercial, and delivery uncertainties

Regular estimate updates incorporate market feedback, early works performance and refined technical requirements. Independent verification of contractor proposals and variations ensures value for money throughout delivery.

Outcomes and Value

TAG Advisory's independent estimation has established robust budget parameters securing Treasury approval and funding commitment for this critical infrastructure investment. Clear separation between capital and operating phases provides transparency for long-term financial planning. Risk-adjusted estimates enable confident commitment to this transformational project despite technical complexities.

Ongoing independent oversight maintains budget integrity as the project progresses through early delivery phases. Regular reporting to Treasury and Public Transport Authority of Western Australia (PTA) executives ensures continued confidence in cost management. The structured approach to whole-of-life costing supports strategic decisions regarding technology selection, delivery packaging and maintenance strategies.

Conclusion

The High-Capacity Signalling project demonstrates TAG Advisory's capability to provide independent cost assurance for highly complex, long-term rail infrastructure programmes. By combining technical understanding with independent rigour, TAG Advisory continues to support the PTA in delivering this transformational investment that will fundamentally enhance Perth's rail network capacity for generations to come.