Systems Engineering Glossary

Term	Definition
Data Item Description (DID)	A formal definition of the structure and content of technical data (requirements specifications, design documents, management data-plans and metrics reports) to be provided to the acquirer of the system by the contractor.
Data Management	A process to plan for, acquire, access, manage, protect, and use technical data over the entire life cycle of a system.
Database	An organized collection of data with a means of identification and retrieval.
Decision Analysis Process	A structured methodology that decomposes a decision to its constituent elements and evaluates them as the basis for making a choice among available alternatives.
Decision Authority	The individual or group responsible for authorizing the transition (at a key decision point) to the next life cycle phase for a program/ project.
Decision Gate	A project review point for review and approval of progress and plans based on entry and exit criteria as the basis for continuation.
Decomposition	The partitioning of a system into components.
Defect	An unintended condition that causes a system to not meet requirements.
Deficiency Report	Identifies problems requiring documentation, coding, or program changes for fielded systems.
Demonstration	A verification technique to assess whether an entity performs its functions in accordance with specified requirements at the same level of decomposition.
Dependency	A cross relationship between requirements at the same level of decomposition.
Deployment	The transfer of ownership of a completed system to the user.
Derived Requirements	Requirements (refined from higher level requirements), such as interfaces, that result from the decomposition of a system design or characteristics.
Design	A process to develop and document a solution to a problem utilizing technology, tools, and experts.
Design Constraints	The boundary conditions the organization must adhere to during execution of the concept and development processes. These conditions can be internally or externally imposed.
Detailed Design	The activity of specifying the internal elements of all program parts; their structure, relationships, and processing; and often their algorithms and data structures.
Discrepancy Report	Documentation of errant conditions that require corrective action.