Rich Hilliard

Software architecture: introducing IEEE Standard 1471

IEEE Standard 1471 identifies sound practices to establish a framework and vocabulary for software architecture concepts.In 2000, the Computer Society approved IEEE Standard 1471, which documents a consensus on good architectural description practices. Five core concepts and relationships provide the foundation for the approved IEEE 1471 version: every system has an architecture, but an architecture is not a system; an architecture and an architecture description are not the same thing; architecture standards, descriptions, and development processes can differ and be developed separately; architecture descriptions are inherently multiviewed; and separating the concept of an objects view from its specification is an effective way to write architecture description standards. IEEE 1471 focuses on both software intensive systems and more general systems, such as information systems, embedded systems, systems-of-systems, product lines, and product families in which software plays a substantial role in development, operation, or evolution.

A documentation framework for architecture decisions

In this paper, we introduce a documentation framework for architecture decisions. This framework consists of four viewpoint definitions using the conventions of ISO/IEC/IEEE 42010, the new international standard for the description of system and software architectures. The four viewpoints, a Decision Detail viewpoint, a Decision Relationship viewpoint, a Decision Chronology viewpoint, and a Decision Stakeholder Involvement viewpoint satisfy several stakeholder concerns related to architecture decision management. With the exception of the Decision Stakeholder Involvement viewpoint, the framework was evaluated in an industrial case study. The results are promising, as they show that decision views can be created with reasonable effort while satisfying many of the stakeholder concerns in decision documentation.

Every architecture description needs a framework: Expressing architecture frameworks using ISO/IEC 42010

The current draft revision of ISO/IEC 42010 (IEEE Std 1471) proposes a formalization of architecture framework within the ontology of the standard. This paper discusses the origin of the concept, motivates its standardization in ISO/IEC 42010, and argues that a well-defined architecture framework should be a key component of any architecture description. The paper describes the application of the proposed construct to several well-known architecture frameworks.

Forces on Architecture Decisions - A Viewpoint

In this paper, the notion of forces as influences upon architecture decisions is introduced. To facilitate the documentation of forces as a part of architecture descriptions, we specify a decision forces viewpoint, which extends our existing framework for architecture decisions, following the conventions of the international architecture description standard ISO/IEC/IEEE 42010. The applicability of the viewpoint was validated in three case studies, in which senior software engineering students used it to document decisions in software projects, two of which conducted for industrial customers. The results show that the forces viewpoint is a well-received documentation approach, satisfying stakeholder concerns related to traceability between decision forces and architecture decisions.

Toward a recommended practice for architectural description

The Architecture Planning Group (APG) was chartered by IEEEs Software Engineering Standards Committee to set a direction for incorporating architectural thinking into IEEE standards. We present a framework for architectural thinking and use it to review existing architectural practices; we summarize the work of the APG and its recommendations and provide the rationale for those recommendations.

Using the UML for architectural description

There is much interest in using the Unified Modeling Language (UML) for architectural description - those techniques by which architects sketch, capture, model, document and analyze architectural knowledge and decisions about software-intensive systems. IEEE P1471, the Recommended Practice for Architectural Description, represents an emerging consensus for specifying the content of an architectural description for a software-intensive system. Like the UML, IEEE P1471 does not prescribe a particular architectural method or life cycle, but may be used within a variety of such processes. In this paper, I provide an overview of IEEE P1471, describe its conceptual framework, and investigate the issues of applying the UML to meet the requirements of IEEE P1471.

Trends in Systems and Software Variability

This article presents the state of the art and practice in system and software variability. It describes the trends driving the increasing importance of variability management, proposes a research agenda, and provides an overview of the articles in this special issue. The Web extra at http://youtu.be/80DAUGahNAY is an audio recording of Davide Falessi speaking with Guest Editors Rafael Capilla and Rich Hilliard about the state of the art and practice in system and software variability.

Realizing architecture frameworks through megamodelling techniques

Most practising software architects operate within an architecture framework which is a coordinated set of viewpoints, models and notations prescribed for them. Whereas architecture frameworks are defined to varying degrees of rigour and offer varying levels of tool support, they tend to be closed: constituent elements are defined in different non-standard ways, they are not re-usable, and the creation of other frameworks requires a complete rework. With the aim to manage this issue, this paper presents MEGAF, an infrastructure for realizing architecture frameworks, which can be used to create architecture descriptions. It builds upon the conceptual foundations of ISO/IEC 42010 for architecture description. MEGAF is realized through megamodeling techniques and is implemented via Eclipse plugins.

On the Composition and Reuse of Viewpoints across Architecture Frameworks

A central aspect of architecting is architecture description. Architecture descriptions take many forms and serve many purposes throughout the life cycle of development, operation and maintenance activities. The use of multiple views -- diverse representations for distinct audiences and uses -- has been a major tenet of architecture description since the earliest work in software architecture. This tenet has been codified in various ways. Most practising software architects must operate within the confines of a prescribed architecture framework (AF) or architecture description language (ADL) as dictated by their organization or client. Current AFs and ADLs are defined with varying degrees of rigour and offer varying levels of tool support, furthermore, these resources are often closed, making it difficult for the architect to tailor a representational solution to the specific challenges of the project at hand. In this paper we propose an automated infrastructure to support the architecture description-related activities of the architect. This infrastructure facilitates customization, composition and reuse of the architects representational resources (AFs, ADLs and their constituents) to meet project-, domain- and organization-specific needs. The proposed approach builds upon the conceptual foundations of ISO/IEC/IEEE 42010 for architecture description. The approach has been evaluated in the context of a complex, real-world, public transportation system.

Characterizing Relations between Architectural Views

It is commonly agreed that an architectural description (AD) consists of multiple views. Each view describes the architecture from the perspective of particular stakeholder concerns. Although views are constructed separately, they are related as they describe the same system. A thorough study of the literature reveals that research on relations between views is fragmented and that a comprehensive study is hampered by an absence of common terminology. This has become apparent in the discussion on inter-view relational concepts in the revision of IEEE 1471 as ISO/IEC 42010 (Systems and Software Engineering -- Architectural Description). This paper puts forward a framework that employs a consistent terminology to characterize relations between views. The framework sheds light on the usage, scope and mechanisms for relations, and is illustrated using several representative approaches from the literature. We conclude with a reflection on whether the revision of ISO 42010 aligns with our findings.