Software Engineering

11
1.2 
Software architecture
1.2 
Software architecture
S
oftware products are a combination of software routines, procedures, modules, 
or objects that provide some functionality. Software, as a substance for developing 
products, does not exhibit physical characteristics. Software is actually a language 
that is transformed into electrical currents within a processing unit that permits 
mathematical calculations. Software commands are translated, which permits data 
manipulations or, for the sake of being precise, functions that represent a basic oper-
ation of a computer yielding a single result when invoked. Therefore, it is essential 
that the software product be designed to address the full set of functional behaviors 
that must be exhibited by the final product. The software architecture represents the 
decomposition of requirements into the functions and subfunctions that are neces-
sary to provide the specified behavior and performance characteristics. Software 
architecture refers to the art and science of designing and implementing software 
products. It involves three partitions: 1) the product requirements; 2) the functional 
architecture, which exhibits functional, performance and resource utilization char-
acteristics; and 3) the physical architecture which establishes the software product 
structural configuration and relationships among structural elements.
The software architecture is analogous to the set of engineering drawings and 
diagrams for a building. The construction of the building does not begin until the 
set of drawings and diagrams have been drafted; are shown to conform to estab-
lished Uniform Building, Mechanical and Plumbing, and National Electrical codes; 
and have been approved by the authorized regulatory agency. Similarly, the imple-
mentation (the design, coding, and testing of modules, etc.) of a software product 
should not begin until the software architecture is complete, can be shown to be 
consistent with the software requirements, and has been authorized by the project 
lead to enter into the implementation stage of development. It is not advisable to 
begin “construction” without understanding the full scope of the engineering 
responsibility.
The software architecture establishes a complete design framework for a software 
product that has been rigorously explored, refined, and scoped to be implementable 
within established budget and schedule provisions. The term 
design
 is defined in the 
Encarta Dictionary
 as “to make a detailed plan of the form or structure of something, 
emphasizing features such as its appearance, convenience, and efficient function-
ing.” This definition identifies four important elements that are examined here as they 
apply to the software architecture:
1. 
Detailed plan of the form or structure of something:
 The term 
plan
 implies a 
set of engineering drawings depicting the various perspectives of a product’s 
form or structure. The software architecture provides several types of design 
diagrams, drawings, or views to represent the unambiguous structure and behav-
iors of the software product. These views are necessary to communicate the 
architectural concepts to members of the software development team and other 
stakeholders.

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