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Subject: Safety-Related Requirements

The Need to Specify Requirements for Off-Nominal Behavior

The Need to Specify Requirements for Off-Nominal Behavior

• SEI Blog
Donald Firesmith

In our work with acquisition programs, we've often observed a major problem: requirements specifications that are incomplete, with many functional requirements missing. Whereas requirements specifications typically specify normal system behavior, they are often woefully incomplete when it comes to off-nominal behavior, which deals with abnormal events and situations the system must detect and how the system must react when it detects that these events have occurred or situations exist. Thus, although requirements typically specify how...

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A Collaborative Method for Engineering Safety- and Security-Related Requirements

A Collaborative Method for Engineering Safety- and Security-Related Requirements

• SEI Blog
Donald Firesmith

Background: In our research and acquisition work on commercial and Department of Defense (DoD) programs, we see many systems with critical safety and security ramifications. With such systems, safety and security engineering are used to managing the risks of accidents and attacks. Safety and security requirements should therefore be engineered to ensure that residual safety and security risks will be acceptable to system stakeholders. The first post in this series explored problems with quality requirements...

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Obstacles in Engineering Safety- and Security-Related Requirements, Second in a Three-Part Series

Obstacles in Engineering Safety- and Security-Related Requirements, Second in a Three-Part Series

• SEI Blog
Donald Firesmith

Background: In our research and acquisition work on commercial and Department of Defense (DoD) programs, ranging from relatively simple two-tier data-processing applications to large-scale multi-tier weapons systems, one of the primary problems that we see repeatedly is that acquisitionand development organizations encounter the following three obstacles concerning safety- and security-related requirements:...

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