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Analyse des données


Dependability is a discipline rich in methods and analyses.

Depending on the field, objectives and systems studied, the type of analysis and methods differ.


Analysing the Reliability, Availability, Maintainability or Safety of a system does not require the same resources. 

Studies are adapted to specific objectives but also to the area of activity :

  • Oil and gas activities;

  • LNG ;

  • Pipelines and hydrocarbon storage;

  • Nuclear industry;

  • Renewable energies (hydraulic, wind, solar, ...);

  • Petrochemical industry;

  • Aeronautics and aerospace.

which are all areas where dependability is applied.

Disponibilité de production

Verify or quantify the profitability of a system

Disponibilité de production



Production availability studies are used to verify or quantify the profitability of an industrial system.


It involves analysing the performance of part or all of an installation, taking into account the different elements that compose it. 

This means considering equipment failures as well as possible reconfigurations, production profiles, site specificities, environmental and/or economic constraints in order to answer the following questions:


Are your profitability projections realistic?


Can you meet your contractual production targets?


How to scale your production tool?


How to optimise your maintenance policy and logistic support?


How to choose the highest performing design and configuration?

Revewing Graphs

The I AU CUBE approach is based on a rigorous methodology that can be developed around four major axis:

  • Analysis of nominal operation and identification of degraded modes.

  • Development of an availability assessment model.

  • Selection of reliability and operational data.

  • Calculation of availability and proposals for improvement.

This approach is based on powerful and proven simulation models such as the GRIF / MOCA-RP computation engine (a dynamic simulation tool developed by TotalEnergies) used for modelling and simulation (based on interpreted stochastic Petri nets).

Other approaches based on the AltaRica language can also be used.

With I AU CUBE, the method is adapted to your needs and not the other way around.

Each system is studied and detailed and the models are adaptive, both in terms of results and of the elements considered.

Sécurité fonctionnelle



With the introduction of standard IEC 61508 and its derivatives for Safety Instrumented Systems (SIS), functional safety has become a major issue in the industrial world. 

This type of approach includes different analysis:

Verification of architectural constraints

Evaluation of the Probability of Failure on Demand (PFDavg)

Evaluation of the Probability of Failure per Hour (PFH)

Verification of Safety Integrity Levels (SIL)

Optimisation of system architectures, test and maintenance policies

Application of standards IEC 61508 / 61511

Depending on the level of requirement and complexity of the system, modelling is carried out by fault trees, safety instrumented loop modelling, Bow-Tie, or even by Markovian approach or dynamic simulation.




The focus is on hazardous accident scenarios and their consequences.

It involves studying the causes of unwanted events using fault trees.

Then, using event trees, the consequences of accident scenarios are analysed.

 A Bow-Tie is thus created. 

This approach makes it possible to check whether the proposed barriers or safety functions are sufficient to limit consequences.

This type of study enables us to :

  • Check whether existing barriers protect against the identified risk;

  • Check whether other barriers are necessary;

  • Identify the level of barriers that need to be added if the risk is not acceptable;

  • Evaluate the frequency of occurrence of an accident scenario.

These comprehensive safety studies combine the SIL “assignment” and SIL “achievement” approaches.

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