Architecture is the arrangement of functions and features within a system that strives for ideal harmony and balance of utility, durability and delight for the stakeholders.
From my (JVS) viewpoint:
the difference between "architecture" and "engineering" is focus. Engineering tends to balance utility (function) versus durability (structural form, strength, cost, risk, etc.) Architects, IMHO, try to balance engineering and delight. Some engineers are also good architects. Some "architecture" is limited to (hopefully sound) engineering. [Stakeholders are supposed to be "delighted" that it works.] Stakeholder delight is hard work, and it's elusive. There are always multiple stakeholders, and their impressions of delight are often in conflict, and changing. Harmony can be elusive. Enduring harmony requires dynamic adaptation. Evolution, or revolution. Graceful, managed growth; or occasional tear-down and rebuild1. It's what architects (designers, modelers) do with houses, products, services, and other forms of systems.
The architecture of an object is the manner in which its components are selected and choreographed into a unified whole designed to satisfy a cohesive purpose. Architecture as a practice is the art and science of designing structures, systems of composite elements, into unified wholes to achieve that purpose. The quality of an architecture can be measured by its social relevance in terms of utility and satisfaction of function, its soundness of engineering and durability, and its esthetic characteristics and the ability to bring delight to its users.
ISO 42010: "The architecture of a system is defined as: 'fundamental concepts or properties of a system in its environment embodied in its elements, relationships, and in the principles of its design and evolution.' ... A system has an architecture even if that architecture is not written down."[bib]Hilliard2011[/bib]
- 1. There is a role for both evolution and revolution. It's a function of context. Urgency sometimes demands faster "fixes" to concerns. That tends toward "redo." Sustained growth tends to need evolutionary methods. Phase shifting (radical transformation in form or substance), even when planned, can be a bumpy path.