Scope of architecture work	The work needed in response to requirements for a changed system. May be divided between small changes handled through change management and big changes that require a substantially new target system. The architecture work has four dimensions of scope: · Breadth: scope of the enterprise, system or solution, · Focus: business, application or infrastructure change · Constraints: the deadline, budget and resources for the work, · Detail: the completeness of the deliverables to be produced.
Scope of enterprise or system	The scope of an enterprise or system has several dimensions; scope views include: · Aim view: Goal/Objective/Requirement catalogue. · System view: Top-level context diagram, or use case diagram. · Process view: Top-level process map. · Data view: Business/Conceptual/Doman Model.
Context Diagram	Shows a system as a ‘black box’, the inputs consumed and the outputs produced by that system, and the external entities (actors or roles) that send inputs and receive outputs.
External entity	An actor or role that inputs to and/or consumes outputs from a system or process. May be an individual or a type. Defining external entities as actors tends to make a model more understandable. Defining external entities as roles tends to make a model more stable and flexible.
Actor	An identifiable individual external entity that plays one or more roles in relation to a system or process. May be a person, a human activity system or a software system. E.g. BACS, salesforce.com, a sales executive, a customer, an auditor.
Role	A part played by one or more actors in relation to a system or a process. With software systems, the part is often to enter or consume data and so named after the input or output data flow. E.g. loan applicant, expense claim approver, auditor.