The Mantua Group

Simple Black and White Asset Management, Reliability Expertise, and Maintenance Execution Perfection.

White Papers

Getting Maintenance Right

From Reactive Operations to First Quartile Performance: Fundamentals, Objective Feedback, and the Cultural Discipline That Sustains World-Class Maintenance Programmes

The distance between a reactive maintenance organization and a first quartile-performing one is not principally a matter of technology, headcount, or budget. It is a distance in discipline. The first-quartile organisation has internalised a small number of fundamentals, has subjected its own work to objective measurement, has brought predictive capability inside its walls so that feedback is continuous rather than episodic, and has built a culture in which precision is a habit rather than an initiative.

Competing Risks, Or Not?

Disciplined Failure-Mode Decomposition for Reliability Data Analysis: When the Risks Framework Applies, When it Misleads, and the Practical Questions That Tell the Difference

The decision to model failure mechanisms as competing risks or to treat them as independent processes requiring separate analyses is among the most consequential a reliability engineer makes. The choice cannot be settled by software, by professional habit, or by the convenience of an aggregated dataset. It can be settled only by a clear understanding of the physics of failure, the timing of risks exposure, and the empirical evidence that two or more mechanisms genuinely overlap on the timeline of an asset’s service life. This white paper sets out the discipline that distinguishes legitimate failure mode competing-risks modelling from analytically convenient over-aggregation, the framework that follows from each choice, and the practical questions a practitioner should pose before adopting either approach.

Asset Management Systems, Asset Performance

Why Certification Does Not Produce Excellence: How High-Performing Organisations Bridge the System-Performance Disconnect

The disconnect is real and widespread. An organisation that has invested in ISO 55000 certification, has populated its asset register, has documented its procedures, and has passed its third-party audit may, in the same calendar year, miss its uptime targets, exceed its maintenance budget, and report no measurable improvement in asset reliability. The organisation has a system. It does not, despite the system, have performance. The certifying body has not erred. The auditor has not erred. The system genuinely is what the certification claims it to be. The error, if there is one, lies in the conflation of the existence of a system with the production of an outcome.

The recognition is uncomfortable because it implicates years of organisational investment. The consultants engaged to support the certification, the internal staff who drafted the procedure library, the senior leaders who sponsored the programme, and the auditors who confirmed its compliance have all, in their respective ways, done what they were engaged to do. The standard has been met. The certificate has been issued. What has not happened in the operational data is the improvement that the organisation expected the certification to produce. The improvement was the goal; the certification, in the organisation’s working assumptions, was the path to it. The assumption was wrong, and the wrongness was structural rather than incidental.

The Right Tool, at the Right Time, at the Right Depth

Elevating Reliability Engineering Decision-Making Through Disciplined Diagnosis, the Right Tools, Proportionate Method Selection, and Organizational Readiness

Reliability engineering offers no shortage of tools. The discipline has accumulated, across roughly a century of formal practice, an arsenal that includes Weibull life-data analysis, fault tree analysis, FMEA and FMECA, root cause analysis, control charts, modal analysis, design of experiments, accelerated life testing, condition monitoring, reliability-centred maintenance, and dozens of variants. The persistent failure mode in the field is not a shortage of tools but a mismatch between the tool and the problem: an over-engineered analysis applied to a question a five-minute hypothesis test would have settled, or a sophisticated technique deployed in an organisation that has not yet developed the foundational disciplines required to absorb its output.

Statistical Rigour in the Regulatory Arena: Weibull Analysis Certification and the Victorian AER REPEX Challenge

How independent Weibull MLE certification, aligned with the AER’s 2024 Asset Replacement Planning guidance, contributed to the evidentiary strength of regulatory proposals across Victorian electricity distribution network submissions.

Victorian electricity network service providers are engaged in one of the most consequential regulatory processes in recent memory. The Australian Energy Regulator (AER) has reviewed the combined revenue and capital expenditure proposals of five Victorian distributors, AusNet Services, Jemena, Citipower, Powercor, and United Energy, for the five-year regulatory control period commencing 2026.

The AER’s draft determination trimmed the distributors’ collective capex claims by approximately $3.7 billion, with the contested quantum approaching $2.9 billion once the revised proposals were filed. Central to the regulatory debate is the quality and defensibility of probabilistic asset replacement expenditure (REPEX) modelling, and, in particular, the statistical validity of the Weibull-based Probability of Failure (PoF) functions that underpin each distributor’s replacement case.

The Mantua Group (TMG) provided independent Weibull Analysis certification and expert advisory services to selected network service providers engaged in this regulatory process. Our work, conducted in alignment with the AER’s 2024 Asset Replacement Planning (ARP) Practice Note and the AER REPEX Model Framework, strengthened the statistical foundation of REPEX submissions across key asset classes, including distribution transformers, substation power transformers, and overhead conductors. This white paper describes the regulatory context, the methodology we applied, and the outcomes attributable to TMG’s involvement.