Inside System Architecture
System Architecture- A Definition
According to the INCOSE SE handbook, “System … architectures depict the summation of a system’s entities and capabilities at levels of abstraction that support all stages of deployment, operations, and support.” This includes “the selection of the types of system elements, their characteristics, and their arrangement”. We need system architecture to synthesize a solution that satisfies system requirements. Developing the system architecture is one of the most important responsibilities of the systems engineer. Think of system architecture as the big picture for a product or infrastructure, which then leads to greater effectiveness and to solutions to difficult problems.
Attributes of Successful System Architecture
The system concept is captured through usage scenarios, system requirements, and performance objectives. The architectural design process consists of attributes that define the architecture, analyze and evaluate the architecture, and finally document and maintain the architecture. The main approach begins by starting with the overall system function (function is a process that transforms inputs to outputs), then performing a top-down and a bottom-up functional analysis. After this, requirements are allocated to functions, and then functions to physical processes. Another key attribute of an architecture is the test-ability of it. All architecture has to be designed with the thought of it being able to be tested or measured somewhere further along in the design process.
Primary Architectural Views of a System
System Architecture documentation is done through the collection of artifacts that communicate the system’s structure, behavior, and qualities. The primary artifact type is the model, which can be graphical, mathematical and statistical (Monte Carlo simulations, etc.), and physical. These artifacts are then organized by architectural views that communicate a certain aspect of the system. Views include perspective and semantics (functional, physical, operational), scope or scale (environment, system, element, etc.), and life cycle (logistics, development, retirement, etc.). These views have diagrams associated with them and are used throughout the design process.
Evaluating System Architecture
Evaluation techniques include scenario tracing, requirements tracing, function evaluation, and other techniques (modeling and simulation, trade studies, architecture trade-off analysis method). Scenario tracing is used to find absences of functionality- shortfalls and redundancy in functionality- overlaps.
