11.2 Software Architecture

Software architecture is the first step in producing a software design.

	The software architecture of a software system is the structure or structures that include its components, the
	visible interfaces of those components, and the relationships among them.

It is a representation that has the following advantages:

		It enables software engineer to analyze design possibility and effectiveness to meet its stated
		requirements

		It enables software engineer to consider alternative architectures at early times when it could be easy to
		make such changes alternatives at a stage when making design changes is still relatively easy

It enables software engineer to reduce the software construction risks.

		Architecture comprises of a fairly small, easy to understand representation of how the system is made
		up and how its various functions interlink.

		Architecture establishes design requirements from an early stage in the development cycle, which leads
		to an efficient and successful project.

11.2 Software Architecture

There are three levels in the design of software systems: These are:

architecture design

code design

executable code design

At the architecture design level, the following is defined:

		System capabilities are identified in the requirements specification with the system components that will
		implement them.

The interconnections among modules are described.

Operators that create systems from subsystems are defined.

At the code design level, the following is applicable:

The system is described at the level of algorithms and data structures, and

		The components are programming language primitives such as numbers, characters, pointers and
		control threads (array, files, procedures, etc..)

	At the executable design level which is a lower level of detail the design engineer discusses memory
	allocation, data format, bit patterns, and so on.