RAMS / Life Cycle Cost Analysis

(Reliability, Availability, Maintainability, Safety)

RAMS is a process to avoid failures already in the planning stage of projects. RAMS Management ensures that systems are defined, risk analyses are performed, hazards are identified and detailed reviews and safety cases are executed and reported. One specific goal is to provide hard evidence to achieve authorization for operations.

Reliability (R)

The probability that an item can perform a required function under given conditions for a given time interval.

Availability (A)

The ability of a system to be in a state to perform a required function under given conditions at a given instant of time or over a given time interval, assuming that the required external resources are provided.

Maintainability (M)

The ability of a system to be in a state or to be reset into a state where a given active maintenance action, for an item under given conditions of use, can be carried out within a stated time interval, if maintenance is performed under stated conditions and using stated procedures and resources.

Safety (S)

Freedom from unacceptable risk for health and personal integrity of humans.

Standards Universe

Fault Tree Analysis

The Fault Tree Analysis (FTA) is the core of RAMS. The FTA depicts the functional system and quantifies all relevant factors to evaluate reliability, availability, maintainability and safety of the complete system. All components of a system will be evaluated systematically and analyzed according to their roles and functions within the system.

Starting at the Top Event (System Failure) all functions and the assigned failure status of the system’s components are evaluated. This results in a Boolean Model (Fault Tree) which is quantified by the characteristic reliability values. The logical linking of events is based on the following graphical elements:

Sample Braking System RAM Analysis - Functional Description

Sample Braking System RAM Analysis - Fault Tree


RIAAT provides a comprehensive system analysis:

  • Evaluation of the soundness of a system:
  • Reliability, Availability and Maintainability (RAM)
  • Check if all Safety requirements are fulfilled (RAMS)
  • Modeling of complex scenarios fosters a better understanding of context, causes and effects
  • Strong visualization of transparent system models
  • Evaluation of critical failure combinations (Minimal Cut Sets)
  • Description of potential for optimization by comprehensive assessment and reporting capabilities
  • Support of probabilistic methods to model uncertainty
  • Intuitive handling of the software
  • In compliance with relevant standards and guidelines


RAMS brochure with full process

Rams Flyer_en.pdf

FSS - Functional System Safety

Balanced, cooperating Safety Systems support the successful application of your procedures and processes.