Category: Security-Related Requirements

In our work with acquisitionprograms, 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 the system must behave under normal conditions, they often do not adequately specify how the system must behave if it cannot or should not behave as normally expected. This blog post examines requirements engineering for off-nominal behavior.

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: