IEEE 42010-2011 pdf free download – Systems and software engineering — Architecture description.
This International Standard takes no position on what constitutes a system within those domains—or elsewhere. The nature of systems is not defined by this International Standard.
This International Standard is intended for use in the domains of systems listed above; however, nothing herein precludes its use for architecture descriptions of entities of interest outside of those domains (for example, natural systems and conceptual systems).
The stakeholders of a system are parties with interests in that system. Stakeholders’ interests are expressed as concerns (see 4.2.3). Stakeholders ascribe various purposes to a system. Purposes are one kind of concern. NOTE 1 The term purpose as used in this International Standard derives from its use in ISO/IEC 15288:2008, 4.31: a system is a combination of interacting elements organized to achieve one or more stated purposes. A system is situated in an environment.
The environment determines the totality of influences upon the system throughout its life cycle, including its interactions with that environment.
The environment of a system can contain other systems. NOTE 2 In this International Standard, the environment of a system is bounded by and understood through the identification and analysis of the system’s stakeholders and their concerns (see 4.2.3).
The architecture of a system constitutes what is essential about that system considered in relation to its environment. There is no single characterization of what is essential or fundamental to a system; that characterization could pertain to any or all of:  system constituents or elements;  how system elements are arranged or interrelated;  principles of the system’s organization or design; and  principles governing the evolution of the system over its life cycle. Architecture descriptions are used to express architectures for systems of interest (see 4.2.2). NOTE 3 The same system could be understood through several distinct architectures (for example, when considered in different environments). An architecture could be expressed through several distinct architecture descriptions (for example when different architecture frameworks are employed). The same architecture could characterise more than one system (for example a family of systems sharing a common architecture)
4.2.2 Architectures and architecture descriptions Architecture descriptions are work products of systems and software architecting. Figure 2 depicts concepts pertaining to the practice of architecture description when applying this International Standard to produce one architecture description expressing one architecture for one system-of-interest. In this International Standard, the term system-of-interest (or simply, system) refers to the system whose architecture is under consideration in the preparation of an architecture description.
The figures and text in the remainder of 4.2 constitute a conceptual model of architecture description.IEEE 42010 pdf download.