Strategy Bridge

Systems Engineering Glossary

Term Main definition

The inability of an entity to perform as intended.


A group of systems that provide similar capabilities that use different approaches to achieve the same goal.  A family of systems does not acquire qualitatively new properties as a result of any interactions among the constituent systems.


Hardware combined with read-only software that is not easily modified.

Float (Schedule)

The length of time an activity can be delayed without becoming a critical activity on the schedule.

Full Operational Capability (FOC)

The state attained when a system achieves full intended operational capability for its specified requirements and is operational in its environment.

Functional Analysis

The process of identifying all of the sub-functions of a system function necessary to perform its goals and objectives.  Relationships and interfaces are captured in the functional architecture.

Functional Configuration Audit (FCA)

The examination of a configured product to verify its performance test results as specified in its functional baseline documentation approved at the PDR and CDR.

Functional Decomposition

An examination of a function to identify (a) sub-functions necessary to accomplish the function, (b) functional relationships, and (c) interfaces.

Functional Flow Block Diagram

A graphical depiction of a system’s functions shown as blocks and their time sequence.