The SEI Attribute-Driven Design (ADD) method is a systematic step-by-step method for designing the software architecture of a software-intensive system. It is an approach to defining software architectures by basing the design process on the architecture’s quality attribute requirements. It follows a recursive decomposition process where, at each stage in the decomposition, tactics and architectural patterns are chosen to satisfy a set of quality attribute scenarios.

Required input to ADD includes known functional requirements, quality attribute requirements, and constraints. Functional requirements may be specified with a feature list or use cases. Quality attribute requirements may be specified using quality attribute scenarios, such as result from an SEI Quality Attribute Workshop. Constraints are design decisions that are forced by outside factors.

Challenges

• How do you design the architecture for a system so that it best meets users' needs?
• How do you meet quality attribute requirements for envisioned systems?
• How do you determine which architectural strategies are appropriate for your quality attribute requirements?
• How can you understand the impact of quality attribute tradeoffs while you're designing a software architecture?

Description

Applying ADD results in the decomposition of the architecture, documented using architectural views, such as those found in the SEI Views and Beyond approach to documenting software architecture. ADD is a recursive method that has two parts:

Part 1: Using tactics to achieve quality requirements

1. Confirm there is sufficient requirements information.
2. Choose an element of the system to decompose.
3. Identify candidate architectural drivers.
4. Choose a design concept that satisfies the architectural drivers.

Part 2: Documenting decomposition

1. Instantiate architectural elements and allocate responsibilities
2. Define interfaces for instantiated elements
3. Verify and refine requirements and make them constraints for instantiated elements.
4. Repeat these steps for the next element.

The ADD method has been used for application domains ranging from information systems to embedded systems. Additional research on systematically producing an architecture design from a set of quality attribute scenarios is underway. Current work is embodied in SEI ArchE, an architecture expert design assistant.

Benefits

The ADD method enables designers to understand quality attribute tradeoffs early in the design process and guides them in designing an architecture that will satisfy both quality and functional requirements.

Who Would Benefit

The ADD method has been used for application domains ranging from information systems to embedded systems.

Availability

The SEI can help you use the ADD method or answer technical questions about ADD. Contact us using the link in the For more information box at the bottom of this page.

Software Architecture Training and Publications

Software Architecture Training at the SEI

Software Architecture Publications

Further Reading

Attribute-Driven Design (ADD), Version 2.0
Rob Wojcik, Felix Bachmann, Len Bass, Paul Clements, Paulo Merson, Robert Nord, & Bill Wood

Integrating Software-Architecture-Centric Methods into the Rational Unified Process
Rick Kazman, Philippe Kruchten, Robert L. Nord, & James E. Tomayko

Managing Variability in Software Architectures
Felix Bachmann & Len Bass

A Practical Example of Applying Attribute-Driven Design (ADD), Version 2.0
William G. Wood

Quality Attribute Design Primitives and the Attribute Driven Design Method
Len Bass, Mark Klein, & Felix Bachmann