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Operational Readiness · Practice Area 01

Reliability Availability
Maintainability
Modelling

Quantifying production availability before and after design decisions are made — so that equipment selection, redundancy levels, spare part holdings and maintenance strategies are based on modelled evidence, not engineering intuition.

Practice AreaOperational Readiness
StandardsISO 14224 · IEC 61649 · MIL-HDBK-217
ApplicationsNew plant design · Existing operations
Primary SectorsMining · Oil & Gas · Power · Process
DeliveryStudy report with Monte Carlo simulation
The Challenge

Availability targets set.
Evidence: none.

Most operational availability targets are set by commercial teams without quantitative analysis of whether the asset system can achieve them. The result is reliability targets that the plant was never designed to meet — and maintenance budgets that cannot compensate for design-stage decisions that have already been made.

01
Availability claims without basis — vendor equipment reliability data used without system-level modelling of how individual failure rates compound.
02
Bottleneck blindness — the constraint in the production system is not identified until the plant is operating and it is too late to redesign.
03
Redundancy under- or over-specification — standby equipment chosen by convention rather than modelled necessity, resulting in either underprotected single points of failure or wasted capital.
04
Spare part holdings not justified — critical spare inventory decisions made without life data or downtime cost analysis to quantify the holding cost versus risk tradeoff.
05
Maintenance resource planning gaps — workforce and contractor resource plans that do not account for the failure rate and maintenance load that the asset system will actually generate.
What is RAM Modelling?

System availability
quantified.

RAM modelling is a stochastic simulation technique that models an asset system — from individual component failure rates through to system-level production availability — using Monte Carlo simulation to quantify the probability distribution of outcomes. It answers the question: given what we know about these assets, equipment and maintenance strategies, what availability can this system actually achieve? RAM models are built from ISO 14224 failure rate data, vendor reliability specifications and operational experience — calibrated to your specific operating environment, maintenance strategy and spare part holdings.

Monte Carlo
Stochastic simulation — typically 10,000+ iterations per model run to quantify the full probability distribution
ISO 14224
International failure rate and reliability data standard — the primary data source for RAM modelling
OPEX
RAM models quantify the maintenance cost and resource demand implications of design choices — before they are locked in
FEL
Front-End Loading — RAM is most valuable when deployed in FEL 2/3 project phases, while design decisions are still reversible
RAM Study Methodology

Model. Simulate. Optimise.

01
System Definition & Block Diagram
Building a Reliability Block Diagram (RBD) of the complete asset system — mapping every equipment item, its redundancy configuration, buffer storage and the logical relationships between components that determine system availability.
02
Failure Rate & Life Data Collection
Collecting failure rate, MTBF, MTTF and repair time data from ISO 14224 databases, vendor specifications, OREDA and operational history — applying appropriate adjustment factors for operating environment, duty cycle and maintenance quality.
03
Maintenance Strategy Modelling
Incorporating the planned maintenance strategy into the model — preventive maintenance intervals, corrective maintenance logistics (spare availability, repair time, contractor mobilisation), shutdown windows and planned production losses.
04
Monte Carlo Simulation
Running the validated model through Monte Carlo simulation — typically 10,000 iterations representing years of simulated operation — to generate the probability distribution of system availability, production throughput and maintenance resource demand.
05
Sensitivity Analysis & Optimisation
Identifying the bottlenecks and key drivers of availability loss — ranking equipment by contribution to downtime and testing design alternatives (additional redundancy, improved maintenance, enhanced spare holdings) to quantify their availability and cost impact.
What You Receive

RAM study deliverables

01
RAM Study Report
A complete RAM study report documenting the system model, data sources, simulation results, sensitivity analysis and recommendations — with sufficient detail to support regulatory review, FEED submissions and board-level investment decisions.
02
Availability Profile
A quantified availability profile for the modelled system — mean availability, P10/P50/P90 estimates and the probability distribution of annual production throughput — expressed in both percentage and production unit terms.
03
Bottleneck & Critical Equipment Register
A ranked register of equipment by contribution to availability loss — identifying the critical items where investment in redundancy, improved maintenance or enhanced sparing delivers the greatest availability return.
04
Maintenance Resource Model
A quantified model of the maintenance resource demand — man-hours by trade, spare part consumption rates and contractor call-out frequencies — enabling maintenance workforce planning and budget development.
05
Scenario Comparison
Side-by-side comparison of design or maintenance strategy scenarios — quantifying the availability and cost implications of each option to support investment decisions on redundancy, sparing and maintenance approach.
06
RAM Model File
The validated RAM model file — enabling future updates as operating data becomes available, design changes are made or maintenance strategy evolves. The model is a living tool, not a one-time deliverable.
Related Services

Services that connect to RAM

GARPI™ 2026 · Global Asset Reliability & Performance Index

How does your reliability
engineering maturity compare?

RAM modelling capability is assessed within GARPI™ Dimension 2 (Reliability Engineering). Find out how your organisation's use of quantitative reliability analysis compares to industry peers — and identify where reliability engineering investment delivers the highest return.

D1
Asset Strategy & Planning
D2
Reliability Engineering
D3
Maintenance Execution
D4
Condition Monitoring
D5
Digital & Data Maturity
D6
Reliability Governance
D7
Workforce Capability
D8
Spares & Materials
Next Steps

Quantify your
availability potential

Whether you are at FEED stage, post-commissioning or trying to understand why a mature plant is not achieving its availability target, the starting point is a scoping conversation about your system, data availability and the decisions the model needs to inform.

Global — Africa & Middle East
Dr Leslie Moyo · Director Africa
enquiries@optimal.world
+44 7932 581 317
Africa — Project Delivery
Danie Fourie CA(SA) · Project Manager
enquiries@optimal.world
+27 82 566 0047
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