The RAMS Engineer

Every system fails. Engineering decides how, how often, and what happens next.

Practical notes, tools and guides on reliability, availability, maintainability and safety, written from real railway and automotive projects.

Try the availability calculator Read the articles
The bathtub curve: failure rate over a product's life, with early failures, a useful life with constant failure rate, and wear-out. Early failures Useful life Constant failure rate λ Wear-out Time Failure rate λ(t)
The bathtub curve. Most RAM predictions assume you are in the flat part. Knowing when you are not is half the job.

Four letters, one discipline

RAMS is how engineers prove a system will work when needed, recover quickly when it does not, and never fail dangerously.

R

Reliability

The ability to perform a function without failure over a given time. Failure rates, MTBF, FMEA, reliability block diagrams.

How often will it fail?

A

Availability

The share of time the system is ready to deliver service. Redundancy, degraded modes, operational availability.

Is it there when we need it?

M

Maintainability

How quickly and easily a failure is detected, located and repaired. MTTR, diagnostics, spare parts, maintenance plans.

How fast can we fix it?

S

Safety

Freedom from unacceptable risk. Hazard analysis, SIL and ASIL, functional safety under EN 50126, IEC 61508 and ISO 26262.

Can it hurt anyone?

Availability calculator

Enter a mean time between failures and a mean time to repair to get the inherent availability and the expected downtime per year.

Mean time between failures
Mean time to repair

Inherent availability

99.960 %

Downtime per year
3 h 30 min
Unavailability
4.00 × 10⁻⁴
Number of nines
3.4

A = MTBF / (MTBF + MTTR), with 8,760 hours per year. Inherent availability ignores logistic and administrative delays, so operational availability will be lower.

Articles

Field notes on methods, standards and the mistakes that cost projects time.

  • Standards

    Functional safety vs RAMS: what is the difference?

    Where IEC 61508 and ISO 26262 stop, and where EN 50126 keeps going.

    In preparation
  • Reliability

    MTBF is not a lifetime

    The most common misreading of a reliability figure, and why it matters in contracts.

    In preparation
  • FMEA

    Ten FMEA mistakes I see on almost every project

    Granularity, detection, and the link nobody makes with the alarm catalogue.

    In preparation
  • Careers

    From automotive to railway safety

    ASIL meets SIL: what transfers, what does not, and what surprised me.

    In preparation

Guides

Practical FMEA for Railway Systems

A step-by-step guide to building an FMEA that engineers actually use: scope, failure modes, detection means, and how to feed the results into availability and safety analyses.

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About

I am a dependability engineer with nearly a decade of experience across the automotive and railway industries, covering both functional safety and RAM.

This site shares what I wish I had found when I started: clear explanations, worked examples and tools, without the vendor pitch. All examples are generic and never taken from client projects.

  • ExperienceNearly a decade
  • IndustriesRailway, automotive
  • FocusReliability, availability, safety
  • StandardsEN 50126, EN 50129, ISO 26262
  • Contactcontact@theramsengineer.com