2. Safety and Environmental Cases/Assessments

System Revision ID ASEMS Document Version Effective From State
4715 3.1 30/09/2022 - 08:00 Extant

2.1. Introduction

The Safety and Environmental Cases can be singularly focussed upon either safety or environment or can be combined to form a Safety and Environmental Case.  The following text refers to “Safety and Environmental Case”, acknowledging that a singular or combined approach can be undertaken.

Note: ASEMS uses the term Safety & Environmental Case to describe the structured argument and body of evidence that supports a Project’s safety claims.  Users are to be aware that alternative terms may be employed by some domains

A Safety and Environmental Case represents a structured argument, supported by a body of evidence that provides a compelling, comprehensible and valid case that the infrastructure, equipment, platform or service is safe for a given application in a given operating environment.

A safety and environmental argument links the available evidence to the claims made regarding the safety and environmental performance of the Products, Systems or Services and should be both compelling and supported by sufficient evidence.  The safety and environmental argument should be articulated in a way that is proportionate to the complexity of the Products, Systems or Services and the level of risk.   A Safety and Environmental Case should provide evidence that:

  1. The infrastructure, equipment, platform or service operating context and its environment has been accurately captured;
  2. Safety and environmental requirements have been met;
  3. Hazards have been adequately identified and analysed and the associated risk has been assessed in an appropriate manner;
  4. All hazards and potential accidents have had controls applied, to ensure all residual risk has been reduced to a level that is As Low As Reasonably Practicable (ALARP);
  5. Environmental impacts are eliminated or reduced, and positive impacts maximised so far as is reasonably practicable;
  6. The system complies with all relevant safety and environmental  legislation, Defence Regulations and MOD Policy;
  7. All measures have been taken to ensure that acceptable levels of safety risk and environmental impacts can be maintained through life.

The degree of evidence required and work involved in developing a Safety and Environmental Case should be commensurate with the risks and impacts posed by - and the complexity and maturity of - the infrastructure, equipment, platform or service.   A Safety and Environmental Case for a simple and / or potentially low risk system should be little more than a safety and environmental  statement and technical leaflet, where a Safety and Environmental Case for a complex and/or potentially high risk system should comprise a significant range of documentation and information.

The generation of a Safety and Environmental Case should start as early as possible in a platform, system or equipment’s lifecycle and should be reviewed throughout that lifecycle to ensure that it remains current and relevant to the actual use and development of the platform, system or equipment.

The Safety and Environmental Case should be reviewed annually and a safety case report issued when:

  1. Any of the requirements change at any stage in the Lifecycle;
  2. Incidents accidents or serious failures occur;
  3. Legislation develops or changes;
  4. There is a change in use or operational context;
  5. Modifications to the Product, System or Service occur; and
  6. On Disposal.

2.2. Safety and Environmental Case Reports

As a Safety and Environmental Case develops throughout the lifecycle, it should be supported by a series of Safety and Environmental Case Reports.  The Safety and Environmental Case Reports should summarise the arguments made and present supporting evidence.  They should document progress against the safety and environmental programme and the arrangements for managing safety and environmental matters through life.

Safety and Environmental Case Reports provide a snapshot of the safety and environmental protection performance of Products, Systems or Services at the time the report is published.  They provide limited assurance at that time of the safety and environmental performance and highlights areas of weakness in the safety or environmental arguments.

Instructions and further guidance for Safety Case Reports can be found in SMP 12.  Instructions and guidance for Environmental Case Reports can be found at EMP 07.

2.3. Version Control

2.3.1. Version 2.3 to 3.0 Uplift

Major uplift from the Acquisition System Guidance (ASG) to online version. 

2.3.2. Version 3.0 to 3.1 Uplift

Update to Clause to reflect update to Policy Clause 5.6.