ESTABLISHING THE SUSTAINABLE ASSET MANAGEMENT MATURITY MODEL (SAMMM) FOR SAUDI METRO SYSTEMS (ISO 55001-ALIGNED) THROUGH RELIABILITY-COST-CARBON SCORECARDS

In this context, Saudi Arabia metro operators are expected to provide reliable passenger service while keeping lifecycle expenditure under control and concurrently making measurable progress towards national decarbonization targets. This paper presents and elaborates a Sustainable Asset Management Maturity Model (SAMMM) that is tailored for Saudi Arabia metro systems and aligned with the requirements of ISO 55001 for asset management systems. SAMMM goes beyond “conformance” by combining: i) a capability assessment based on ISO clauses, ii) a five-level maturity ladder, and iii) an integrated set of RCC scorecards using MCDA. The proposed approach provides an auditable link between strategic intent, such as the pathways of the Saudi Arabia Green Initiative, and day-to-day asset decisions like maintenance strategies, renewal planning, and procurement. To make the model actionable, the paper defines KPI families, normalization rules, weight elicitation, and governance practices, and a practical implementation roadmap supported by visual management tools such as framework diagram, maturity ladder, and ISO clause radar chart. Riyadh Metro serves here as an illustrative context to demonstrate how SAMMM can structure progress from early-stage data stabilization to predictive maintenance and low-carbon procurement, while concurrently maintaining high reliability.