scope:

This standard applies to the development, modification or bringing in to use of safety-related software on the railway.

It applies to the tools or methods used for the derivation, preparation or verification of software code, data, and supporting information (e.g. configuration).

Additionally, this standard applies to the tools that are used to develop or control deployment of safety-related software (e.g. software updates).

The scope also includes the interface with operational and maintenance systems, including the interface to people who may use the software as part of a safety function.

This standard applies equally to both external suppliers and LU internal teams.

The requirements of this standard form part of the assurance of railway safety, and the standard supports the railway safety assurance processes and LU category 1 standard S1538.

The requirements of this standard are not applied retrospectively to projects that are underway at the time of issue, or have been assured through prior software safety standards. The standard shall typically apply to subsequent changes (but see note 5 below).