Systems Engineering Terminology
– Two or more parts or subassemblies joined together to form a complete unit,
structure, or other article.
– An estimate or determination of the value of a process against a scale of
– A configuration identification document or a set of such documents, formally
designated and fixed at a specific time during a configuration item's life
Bill of Materials
– A listing of all subassemblies, intermediate parts, and raw materials that are
needed to produce one unit of a finished product.
– A diagram of a system, computer, or device in which the principal parts are
represented by suitably annotated geometrical figures to show both the functions
of the parts and their functional relationships. (IEEE 610.12-1990)
– Pertaining to a method or procedure that starts at the lowest level of
abstraction and proceeds towards the highest level.
– A study designed to study intensely one set (or unit) of something as a
distinct whole, with the goal of understanding the set as a distinct whole in
its particular context.
– The process of confirming that a system or component complies with its
specified requirements and is acceptable for operational use.
– (1) The ability of two or more systems or components to perform their required
functions while sharing the same hardware or software environment.(2) The
ability of two or more systems or components to exchange information.
– One of the parts that make up a system.
Concept Phase –
The identification and exploration of alternative solutions or solution concepts
to satisfy a validated need.
– The application of multiple engineering disciplines to develop requirements in
several different but related areas at the same time so the requirements and
solutions are coordinated and mutually supportive.
(CI) – An item under
development that is designated for configuration management.
(CM) – The
process of evaluating, approving or disapproving and coordinating changes to
– The document defining how configuration management will be implemented
(including policies and procedures) for a particular acquisition or program.
(COTS) – A
special case of non-developmental item (NDI) that has been developed to meet a
commercial strategy and is available for general purchase.
Concept of Operations
- A document identifying
the ways in which a system or piece of equipment will operate, including any
limitations, restrictions, safety factors, reporting capabilities, etc.
– An approach to product development that fosters a unified, collaborative
effort by and integrates inputs from business, engineering, manufacturing, and
management specialists across the traditionally segregated phases of product
Contract Data Requirements
– A form used as the sole list of data and information which the contractor will
be obligated to deliver under the contract.
Cost as an Independent
Variable (CAIV) –
An engineering approach in which analyses center around the ability to meet
stated cost objectives.
Cost of Ownership (COO)
– The purchase price of equipment plus the cost of operating this equipment over
its projected life span .
Critical Design Review
(CDR) – A
review conducted to determine that the detailed design satisfies the performance
and engineering requirements of the development specification.
Data Requirements List (DRL)
– A list of data and information to which completion of an engineering effort is
– The period of time during which the designs for architecture, components,
interfaces, and data are created, documented, and verified to satisfy
– A determination of the technical adequacy of the systems engineering and
design efforts in meeting system requirements.
Design for Test (DFT) –
The practice of adding hardware hooks to integrated circuits in order to
facilitate effective, inexpensive testing.
Design for Testability
aspects of the product design process whose goal is to ensure that the
testability of the end product is competently and sufficiently developed.
Manufacturing Development (EMD) –
That phase of acquisition during which the concepts validated in the previous
phase are transformed to system and manufacturing process design.
– Those aspects of the system design which cover fault monitoring (detection),
fault response, fault storage and fault annunciation, for both operational and
– The process of identifying and determining performance of the functions
necessary to achieve mission requirements. Also, the process of examining the
characteristics of a defined function to identify all of the sub-functions
necessary to the accomplishment of that function.
Life Cycle Cost (LCC)
– The total cost of acquisition, operation, maintenance, and support of an item
throughout its useful life, and including the cost of dispersal.
Military Off the Shelf –
an existing item designed and in service in other military projects. Also called
Non-Developmental Item (NDI)
– an existing item designed and in service in other military projects. Also
called Military Off-the-Shelf.
& Maintainability (RAM)
– A requirement imposed on acquisition systems to ensure they are operationally
ready for use when needed, will successfully perform assigned functions, and can
be economically operated and maintained within the scope of logistics concepts
Request for Proposal (RFP)
– A formal process by which the government asks contractors to submit proposals
for satisfying a procurement or acquisition requirement.
– The process of transforming user needs and requirements into an integrated
system design solution through concurrent considerations of all life cycle needs
including development, test and integration, production, operation and full
integration support. Cost and risk reduction are an integral part of Systems
– A structured process which compares options using predefined performance
criteria, to result in the selection of the best design that satisfies all
requirements. Trade studies are highly iterative and are used during all
development phases to ensure that all factors which might impact a function or
requirement are considered.