System/Grid Architecture and Architecture Specifications
What they are and why they matter.
A system architecture is the highest-level description of a complete complex system; a power system or grid architecture is the highest-level description of a complete (ultra-large-scale) complex power system. It enables us to reason about the system and its interactions and behaviors. It consists of three kinds of elements:
Structure – the shape of the system
Components – the elements or parts making up the system
Externally visible characteristics – how the system behaves as seen by the operators and by the users
Structure refers to the ways that the components are connected, related, or interact. Structure is mainly responsible for setting the essential bounds on a system and determining what it can do and what it is not permitted to do.
Components, be they hardware, software, organizations, etc., are treated as black boxes, meaning that the architecture is not concerned with how the elements work (what is inside the boxes), but only with their functions and performance as seen from outside. The insides of the black boxes are exclusively the domain of the developers, integrators, and system operators.
There are two classes of grid architecture characteristics: those seen by the builders and operators of the system (called properties) and those seen by the users and customers (called qualities). It is essential to recognize and delineate these two classes for architectural purposes.
Among its many purposes are:
Answer questions about the system, its behaviors, and alternatives.
Manage system complexity and therefore support decision-making about the system.
Trace the impact of changes to avoid unintended consequences.
Support risk management in transforming a complex system.
Help stakeholders understand the whole system and the implications of change.
Identify and remove or modify existing structural barriers to new capabilities.
Identify gaps in technology, organization, regulation, business processes, etc.
Future-proof technological investments.
Manage integration costs.
Enable the creation or improvement of intrinsic characteristics that bolster resilience, capability, and affordability.
The architecture model allows teams to simulate and analyze system behavior, compare alternatives, estimate performance, and catch concept flaws before actual implementation
An architectural specification is an enforceable set of constraints on system “shape” (structure, system/component function, and component allocation), intended to ensure that the system is capable of meeting objectives while not behaving badly. It consists of a formal description and depiction that outlines a system’s structure, components, and behavior. It bridges high-level requirements and physical implementation, serving as a technical blueprint for stakeholders to guide development, manage constraints, and ensure quality. The specification is a set of documents, diagrams, and models. Designs and implementations conform to the architecture.
Significant But Non-Obvious Benefit
A well-formed system architecture simplifies downstream decisions and frees up architects and engineers working on individual components, algorithms, or systems to employ creativity with assurance that unintended consequences will not crop up to hamper or even invalidate their work.
Imagine trying to build a house by inviting all the contractors (excavators, concrete workers, framers, plumbers, electricians, finishers, drywall installers, painters, cabinet makers, etc.) to an open grassy field and telling them to just go ahead and build the house. They need a plan, a blueprint.
That is what the architecture specification is for. It’s the blueprint to which the implementers adhere in order to ensure that it all goes together.