The importance of the SRACs in a Railway RAMS Study

What is a SRAC? What is an exported risk? In this article, we explain it in detail

SRACs is the acronym for "Safety Related Application Conditions". In railway slang and CENELEC nomenclature in a Safety Case, SRACs are also called Exported Risks.

The concept of SRAC is defined on CENELEC EN50129 standard and it is the task of the RAMS team of a project to develop the documentation appropriately to be delivered to the user. 

As a reminder, in a RAMS Safety Study or Railway Safety Case, most safety analyses and arguments are directed towards characteristics, performance and attributes of products or systems.

In a rigorous analysis process through RAMS Engineering, hazards must also be identified (hazards) that CANNOT be covered by such characteristics, features or attributes, but through strict compliance with certain requirements during the use (exploitation) of the product or system. This set of requirements are called SRACs.

SRACs must be seen as a legal contract associated with the transfer of a device or an installation, with connotations related to safety.

Its importance requires robustness and its treatment must meet expectations regarding the implications that they entail.

In this way, SRACs identify the conditions in which a product or system must be used, from all perspectives and points of view, due to safety-related reasons, to avoid the occurrence of risks. Compliance with these conditions' responsibility of the user. 

SRACs clarify the safety responsibilities of the entities in charge of the installation, maintenance and operation, that is, of the entire service cycle of the equipment or installation.

SRACs are normally divided in the following 3 types:

1. Those that regulate the use of a product within a larger system, where linkages and interrelationships with other products will appear. When becoming part of a more complex system, they should be used conveniently and according to certain characteristics
2. Compliance by the installer, the maintenance technician or the end user of a set of minimums in relation to the use of the product or the system concerned
3. Product limitations that, if not respected, may cause some risk. Normally these limitations would tend to be resolved by the same product. However, due to limitations of the state of the art or costs, its use will be conditioned by these limitations.

In many cases, SRACs are considered by the end user as a problem, receiving responsibilities and obligations outside their scope or reach. And sometimes it is certainly so.

A good transfer of knowledge, a good action plan for reducing or mitigating the number of SRACs. In many cases, criteria and common sense can reduce the negative feeling that the end user has about SRACs being exported.

In Leedeo Engineering, according to our experience, we identify important points to take into account for the development of a correct transfer of SRACs:

• The end user (installer, maintainer, operator) must fully understand each one of the Risks being exported. It is mandatory to invest time in ensuring that all parties have fully understood each one of the SRACs that should be taken care of.
• Limiting the maximum number of SRACs. It is important to distinguish what is an SRAC and try NOT filling gaps of a product or a system using an SRAC.
• Promote activities, actions and tests between the developer and the end user, by mutual agreement, in order to reduce or redefine SRACs.
• Avoiding SRACs in the form of unreasonable demands for the end user, from a technical, economic or temporary point of view.
• Avoiding ambiguities and/or SRACs conditioned by certain situations or events.

Defining, identifying and transferring SRACs in a correct way within a process of studying RAMS Railway Engineering can mean for a technologist a way to be able to supply products, ensuring there will be no impact on safety. This is undoubtedly bound by any developer of products, systems or facilities within the railway sector.

For an end user such as Railway Administration or a maintenance company, it will be vital to request, understand, mitigate and if possible, reduce, SARCs which will be your responsibility from the moment that this product, system or installation will be acquired.

From a strict point of view of LLC (Life Cycle Cost) and, obviously, a product or system should never be purchased without knowing corresponding Safety-related Application Conditions (SRACs).

In Leedeo Engineering, we have extensive experience in audits, analysis, development and documentation of SRACs (Safety Related Application Condition) in the field of railway RAMS projects, in accordance with CENELEC EN50126 standards.

Some of our latest projects are:

• Engineering and documentation of SRACs according to characteristics, performance and project or scope of the product or the system.
• End customer support as an independent part for study, audit, checks on documentation, mitigation actions of SRACs, as well as quality assurance in the transfer process and fit of the SRACs.