Microsoft .NET: Architecting Applications for the Enterprise ... - BattleIT

Chapter 1
Architects and Architecture Today
The purpose of software engineering is to control complexity, not to create it.
—Dr. Pamela Zave
At the beginning of the computing age, in the early 1960s, the costs of hardware were
largely predominant over the costs of software. Some 40 years later, we fi nd the situation
to be radically different.
Hardware costs have fallen dramatically because of the progress made by the industry.
Software development costs, on the other hand, have risen considerably, mostly because of the
increasing complexity of custom enterprise software development. Cheaper computers made
it worthwhile for companies to add more and more features to their information systems.
What in the beginning was a collection of standalone applications with no connection to one
another that barely shared a database has grown over years into a complex system made of
interconnected functions and modules, each with a particular set of responsibilities.
This situation has created the need for a set of precepts to guide engineers in the design
of such systems. The modern software system—or the software-intensive system, as it is
referred to in international standards papers—can be compared quite naturally to any
construction resulting from a set of detailed blueprints.
Appropriated from the construction industry, the term architecture has become the appropriate
way to describe the art of planning, designing, and implementing software-intensive systems.
In software, though, architecture needs less artistry than in building. Well-designed buildings
are pleasing to the eye and functional. Software architecture is less subjective. It either functions
as required or it does not. There is less room for artistry and interpretation, unless you want to
consider the artistry of a well-crafted algorithm or a piece of user interface.
One of this book’s authors had, in the past, frequent interaction with an architecture studio.
One day, a question popped up for discussion: What’s architecture? Is it an art? Or is it just
building for a client?
In software, the term architecture precisely refers to building a system for a client.
In this fi rst chapter, we’ll look at some papers from the International Organization for
Standardization (ISO), the International Electrotechnical Commission (IEC), and the Institute
of Electrical and Electronics Engineers (IEEE) that provide an architectural description of
software-intensive systems. From there, we’ll give our own interpretation of software
architecture and voice our opinions about the role and responsibilities of software architects.
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