Australian mining safety regulation has shifted decisively from compliance auditing towards risk based approaches grounded in critical control management (CCM) and high reliability organisation (HRO) thinking. In Queensland, the Resources Safety and Health Legislation Amendment Act 2024 (State of Queensland, 2024) makes CCM a prescribed requirement, with the post-grace-period compliance test commencing on 1 June 2026. Regulators and boards are no longer satisfied with evidence that a procedure exists; they are asking a harder question: how reliable are critical controls under real operational conditions? Traditional reviews remain largely binary: control present or absent, inspection done or not, which creates a false sense of assurance that fatally weak controls appear fully compliant. This paper describes Control Effectiveness Assessment (CEA), a structured, field-tested methodology that directly addresses that question. CEA combines the Energy Damage Model, the hierarchy of controls, and human-centred design principles to evaluate not only the presence of critical controls but also their practical reliability. Multi-disciplinary workshops with subject matter experts (SMEs) and frontline personnel score each control on four interdependent dimensions: Robustness, Human Dependency, Alignment and Adaptability. The output is a quantitative reliability profile that exposes where controls are fragile, overly human-dependent or not aligned with how work is actually done. Beyond a single assessment, the workshop architecture turns the workforce into a distributed sensor network for control health, it surfaces drift in control dependability over time as a leading indicator of failure, and provides defensible evidence of ‘reasonably practicable’ decision-making. Using an anonymised critical-risk case study in mobile equipment and driving safety from a large Australian asset-intensive operator, the paper demonstrates how CEA exposes the gap between work-as imagined and work-as-done, differentiates true hard controls from supporting administrative measures, integrates digital indicators into a meaningful picture of control health, and offers an effective framework that mining operators can apply to focus assurance efforts on the controls that actually matter.