Software Engineering

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12.1 
Structural design solution
direction with one source of information and one destination; it may be bidi-
rectional with multiple sources and destinations of shared data; or it may be 
a broadcast-type interface in which a source broadly transmits data to any 
and all qualified receivers.
●
 
External interfaces
—identifies the data exchange protocol and format for 
data shared among interfacing (communicating) systems and applications. 
An interface is a formal agreement among system developers that commits 
both sides to conform to the interface control document that describes the 
interface.
a.
 
External systems
—an external system or software application that the 
software product under development must interface with to collabora-
tively achieve some purpose.
b.
 
Database management system (example)
 —a common example of an 
external software application with which a software product may be 
designed to operate and interface.
The software product configuration is comprised of a number of structural 
units that are combined and integrated into structural components. Structural com-
ponents are larger configuration elements that are comprised of a set of integrated 
structural units and/or components. The integrated set of structural components is 
used to describe the software product configuration that is intended to be delivered 
to customers, stakeholders, or consumers. Structural units and components are the 
product elements that will be implemented, tested, and managed throughout the 
software life cycle.
It may be necessary to create assembly configurations (structural assemblages) 
to support software integration and testing. A structural assemblage represents an 
intermediary engineering structure that involves additional software (test stubs) that 
supports software integration and testing (e.g., test harness in the hardware manu-
facturing vernacular).
Structural assemblages identify the structural units, components, and test stubs 
that will be assembled and integrated to support software testing. Structural units 
do not appear in the structural assemblage configuration since they are integrated 
into structural components as the first level of assembly and integration. Any test 
stubs necessary to support structural unit test and evaluation are not relevant to the 
structural assemblage configuration since they have outlived their usefulness at the 
structural assemblage level of integration and testing.