What is a system architect? As surprising as this is, a crabby old edition of Webster's dictionary does a damn good job of explaining it. The first definition for system given is "a regularly interacting or interdependent group of items forming a unified whole." The word comes from the Greek syn, with/together, and histanai, to stand. Architecture is defined as "formation or construction as or as if as the result of conscious act" (this is the second definition; the first one involves the usual specific habitable-structures definition). The architect is defined as "one who plans and achieves a difficult objective." The word derives from the Greek archein, to begin or rule, and tekton, builder or carpenter.

The system architect conceives of, and formally describes in terms sufficient to direct implementation, the way diverse components relate to and interact with each other, in pursuit of a functional objective. The paramount mental process of the system architect is the holding in the mind of a fully understood and deliberate model of the system, allowing evaluation of performance and adjustments based on an understanding of the system and observation of the model's performance. Thus, before a system ever exists in the outside world, it exists as a fully functioning construct inside the mind of the system architect.

The system architect does not actually implement the designs he has conceived. Instead, he describes the design in great detail, and communicates this description to others, who implement the design under the guidance of the architect. The architect constantly compares the progressing implementation to the design and to the running mental model of the system, and when discrepencies arise, adjusts the implementation or the design (and sometimes both at once) to restore strict registration between the two. The functional objective is not itself subject to amendment.

The system architect is no more an infallible individual than is any other. Thus, discrepencies do arise. A good system architect is comfortable with this inevitability, and responds with grace and agility when errors and oversights are encountered. He appreciates the skill, purity of intent, and constraints of those who implement his design, as those who implement his design appreciate the skill, purity of intent, and constraints of the system architect.