Solution architecture (within or without enterprise architecture) is an architecture domain that aims to address specific problems and requirements, usually through the design of specific information systems or applications.
Solution architecture is either:
- Documentation describing the structure and behaviour of a solution to a problem, or
- A process for describing a solution and the work to deliver it.
The documentation is typically divided into broad views, each known as an architecture domain.
Where the solution architect starts and stops work depends on the funding model for the process of solution identification and delivery. E.g. An enterprise may employ a solution architect on a feasibility study, or to prepare a solution vision or solution outline for an Invitation to Tender. A systems integrator may employ a solution architect at “bid time”, before any implementation project is costed and resourced. Both may employ a solution architect to govern an implementation project, or play a leading role within it.
Typical outcomes of solution architecture.
Solution architects typically produce solution outlines and migration paths that show the evolution of a system from baseline state to target state.
A solution architect is often but not always responsible for design to ensure that the target applications, in a technical architecture, will meet non-functional requirements.
A solution architecture description (or solution outline) will typically be an abstraction of an end-to-end subsystem, consisting of application software supported by middleware which together provide:
- An IT implementation of a specific business task or process necessary to support a business function with appropriate non-functional requirements (e.g. integrity, performance, security, recoverability, etc.)
- A synchronization mechanism between the subsystem consumers/providers and the associated business task or process
e.g. an end-to-end eCommerce subsystem which allows customers to place orders for goods and services or an end-to-end Supply Replenishment subsystem which enables an enterprise to order new stock from its suppliers.
Generally speaking, an enterprise architect’s deliverables are more abstract than a solution architect’s deliverables. But that is not always the case, and the main distinction between enterprise architect and solution architect lies in their different motivations.
The solutions architect is primarily employed to help and support programme and project managers in the design, planning and direction of implementation projects. The enterprise architect is primarily employed to identify and direct strategic and cross-organisational solution delivery.
A solutions architect may also report to an enterprise architect, but the strength of that reporting line varies between organisations. The influence of the enterprise architect team on solution architects depends on an organisation’s policies and management structure. So, the extent to which a solution architect’s work realises an enterprise architect’s road maps will vary widely in different contexts.
See also 
- Segment architecture, a subdivision of enterprise architecture. A solution architecture may cut across several segments.
- “Patterns of enterprise application architecture” by Martin Fowler.
- End-to-end subsystem defined within Patterns for e-business at http://www.ibm.com/developerworks/patterns/library/definitions.html