Chapter Three. Software Architecture: Basic Training

This chapter on basic training for software architects presents the fundamental tools required of effective software architects. In the military, basic training is used to challenge and motivate cadets and to demonstrate both the demands and rewards of a military career. Similarly, software architects must be motivated individuals who have the desire to confront the challenges of technical leadership in a software development effort. However, motivation is not enough. A software architect must be equipped with the intellectual tools to realize an architectural vision.

This book takes a hands-on approach that not only presents the best architectural practices in the industry but also provides concrete real-world examples and exercises for applying the presented material to circumstances common throughout the software industry. Basic training will cover the fundamental concepts of software technology, which provide a foundation for software architecture. Software technology has evolved through many trends and alternatives for software development. Currently, mainstream software practice has evolved from procedural to object-oriented to component-oriented development (Figure 3.1). With the increasing adoption of enterprise Java and Microsoft .Net, component orientation is the next major paradigm. In corporate development, most new-start projects are adopting component orientation because it is supported by the majority of commercial development environments. As is discussed in this chapter, object orientation has a very weak notion of software architecture, which leads to serious shortcomings. The emerging trend of component orientation is replacing old approaches with strong elements of architectural design.

Software architects must be able to articulate these development paradigms clearly, along with appropriate uses of enabling technologies. In any given project, an eclectic mixture of development paradigms (including relational database management) can be useful to achieve the best results. Each paradigm has something useful to offer, including mature development tools.

Today, most organizations will find their technology skill base engaged in one of the three major paradigms: procedural, object oriented, or component oriented. Each paradigm is highly specific to the organization and its staff skills. Procedural and object-oriented paradigms are closely tied to programming language choice, but component orientation is different in that it is more closely associated with the selection of an infrastructure.

Procedural programming languages include FORTRAN, COBOL, C, Pascal, and BASIC. In procedural technology, the program comprises the process for executing various algorithms. The process is separated from the data in the system, and the process manipulates the data through direct access operations. This is a direct outcome of the stored-procedure programming systems from which computer technology originates. When the program and data are separated, there are many potential interdependencies between parts of the program. If the data representation is modified, there can be substantial impacts on the program in multiple places.

An example of data-process separation is the year 2000 problem, in which simply adding some additional digits to the date representation had catastrophic consequences for procedural software. Unfortunately, because the majority of systems are built with procedural technology, the dependencies upon these data representations can cause system-wide program errors and the necessity for line-by-line program review and modification.