Software Engineering

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CHAPTER 3 
Software Architecture
be determined by the magnitude of the customer base and the reliance of busi-
nesses or individuals on the product to achieve their professional transactions.
3.2 
 Software requirements baseline relationships and 
dependencies
The software requirements baseline consists of a number of specifications that are 
harmonized to articulate the expected functional, performance, physical, and qual-
ity characteristics to be exhibited by the software product, computing environment, 
and associated post-development processes. This set of requirements focuses on the 
activities that elaborate the software architecture and the definition of the accept-
ance test scenarios and procedures. The requirements are utilized during the func-
tional and physical configuration audits as the standard against which software 
product implementation is assessed to determine its quality of workmanship. The 
requirements baseline involves the following relationships and dependencies with 
stakeholder needs or other elements of the software architecture:
1. 
Development costs versus timeliness (Stakeholder Needs).
 The software require-
ments will ultimately determine the cost of the development effort and will 
impact the product delivery milestones. Determining how to balance the soft-
ware product requirements so that the development project remains stable and 
can proceed decisively toward conclusion is contingent on the accuracy and 
reasonableness of the requirements baseline to establish the conditions for the 
project to succeed.
2. 
Software product requirement appropriateness (functional architecture).
 The 
suitability, correctness, thoroughness, and precision of product requirements 
will impact the development effort. The breadth of the requirements will affect 
the product success in the marketplace. The software product requirements are 
interpreted and converted into the functional architecture. Vague or ambiguous 
requirements may obscure the optimal composition of the functional architec-
ture in terms of orderly arrangement, complexity, and suitability. Requirements 
that are overstated will drive up development costs and threaten to increase 
product complexity.
3. 
Scope of the test and evaluation effort (test and evaluation).
 The requirements 
baseline establishes the scope of the test and evaluation effort for both the 
software product and the post-development software sustainment (PDSS) pro-
cesses. Permitting the requirements to be excessive will significantly increase 
the number and complexity of test cases and scenarios. The testing effort may 
consume a significant amount of project resources in terms of budget, tools, 
equipment, and schedule.
4. 
Scope of the post-development processes (post-development processes).
 
Increased product complexity impacts ease-of-use and training demands for 
users, as well as product and customer support costs.

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