The principal viewpoint set used within the Unified Process for engineering cyber systems is Philippe Kruchten’s 4+1 View model. It seperates concerns about the architecture of the system into four views, each with identified and distinct concerns, and ties the views together using scenarios defined as Use Cases. The Logical and Process views in combination [left side] form a behavioral view of the system. The Development and Deployment (Physical) views in combination [right side] define the mechanics of accomplishment.
The benefit of the model is its general acceptance as a standard framework for engineering of cyber systems, and it is integrated with a standard language for expression of the views, the Unified Modeling Language (UML). It is also consistent and foundational to other engineering tooling developed by the Object Management Group which are based on variations and extension to UML as an engineering language for cyber development and maintenance.
Architected Futures uses OMG UML frameworks for consistency of framing of engineering. The methods were developed in the early 1990’s through a gradual integration of numerous framing sets which had been developed prior to that time. Most modern engineering documentation related to cyber follows a variant of UML. A general understanding of UML symbols and diagramming conventions, along with an understanding of the 4+1 viewpoint model is useful as a universal language for expression of models and concepts of cyber architectures.
The common UML perspective diagrams used to express the 4+1 views, or portions thereof, are:
- Logical View
- End User
- Composite Structure
- State Machine
- Process View
- System Integrators
- Composite Structure
- Development (Implementation) View
- Physical (Deployment) View
- Systems Engineering
- Operational System Administration
- Use Case
AIR Business Views Model
The Kruchten model provides a well rounded model for engineering and communicating the cyber mechanics of a system. However, it is a model created by engineers for purposes of quality management of engineering. It reflects the interior of cyber systems, rather than their intent. The difference has been problematic is managing the architecture of mixed environments since the beginning of time. Design of the tooling, versus design of the systems in which the tooling is intended to operate; and managing the design of the symbiotic evolution of the two as one system. It’s perfectly understandable how and why engineers want to assign a viewpoint to users in order to elicit requirements for the design of the cyber components of the combined system, but Class Diagrams rarely speak to the logical view of business activity for users.
The AIR Business Views Model was developed to provide a 360 degree set of views from the perspective of the business context of the cyber-physical system as a unit. A single cyber system has many users, wearing many hats, all of which need to be accounted for in what the 4+1 model reduces to a single End User.
AIR Business Views Model
EATS 5+1 View Model and Framework
The AIR Business Views Model by itself is similar to the Kruchten model with the Use Case Scenario view which pulls things together. In addition, it implies a singular principal party associated with each principal viewpoint, which is not the case. EATS uses an expanded version described as a 5+1 View Model which also shows shared concerns on the part of system owners and stewards when considering the integration of cyber and human components as part of consolidated business activity, and the full lifecycle of business systems, not simply a one project development and release to operations of a set of cyber components.
5+1 View Model
As an architectural planning and reference, the 5+1 model is still one dimensional. To be fully useful, each view needs to be understood from multiple levels of abstraction, similar to the Zachman Framework. This leads to an expanded viewpoint set to fill out a utilization viewpoint matrix for the cyber components integral to the same framework of views describing the real world operational concerns.
5+1 View Framework
Architecture Cube View
The 5+1 View Framework is intentionally constructed using the same vertical row structure as the EATS Zachman Viewpoint Framework.
EATS Zachman Viewpoint Framework
Combining the two provides a 3 dimensional viewpoint cube which provides a fine grained schematic for isolating and evaluating the components of a cyber-physical system’s architecture, and the relative effectiveness of satifying intention for the full set of stakeholders whose concerns need to be addressed.
EATS Architecture Cube
From an analytical perspective the standard aspect of the cube tends to be the height, the abstraction levels, which has the most consistent utility. Otherwise, what the cube represent is an enclosing solid which forms a prismatic understanding of intent and effectiveness in achieving intent on the part of the evaluated composite system as an arrangement of constituent parts, evaluated from a multi-prismatic set of observational lenses.
This allows architectural dynamics to be evaluated as a function of effects in the transformation of a particular configuration of an EATS Architecture Cube into an adjusted EATS Architecture Cube as a function of symbiotic support, operational component exchange or replacement, or evolution as depicted in the next diagram.
Architecture Correlation and Transformation Viewpoint Mapping
Symbiotic alignment is a key factor in the evaluation of overlapping architectures as is the sample case shown below, where different divisions of a conglomerate may be require to align with different, potentially orthogonal, contexts.
Corporate and Industry Architecture Correlation Mapping
Component replacement, expansion, and whole system evolution toward goals are able to be completely evaluated using the cube models as shown in the planning example below.
Architecture Evolution Mapping