What are the Types of Architecture Diagrams?

Hi All, I am posting a few items I hope may help someone understand digital architecture, or accelerate their work by useful templates.  I hope you find them useful.

In my experience over the last 10 years, I have used the following diagrams…

Conceptual Architecture Diagram — this is a basic / abstract, lightly-technical diagram that highlights the relationships between key components and is often workflow oriented. Simply stated, it depicts the strategy of the solution within a context. This is valuable because it forms the basis for a viable solution implementation and a way to get initial agreement of the direction of the solution and isolate domain areas. It forms the basis or structure for the Logical Architecture diagram. It is the responsibility of a Solution Architect.

Logical Architecture Diagram — This is the next step after the Conceptual diagram(s). Logical diagrams describe how a solution works in terms of function and logical information. It illustrates connectivity between applications and therefore the flow or sequence between components. The value is that this helps instruct the software development teams on how to implement a solution but without reference to code, coding or related implementation techniques. And, it forms the basis for the physical architecture and documents the system for troubleshooting, upgrades and even potential future migrations. It is the responsibility of a Solution Architect.

* some organizations combine Conceptual and Logical diagrams

Physical Infrastructure Architecture Diagram — This depicts physical elements that enable the infrastructure team to do their work including server models/VMs/Containers, databases/storage, network, zones, systems and sub-systems, and connectivity. This is very detail oriented in order to successfully implement the physical architecture. It is generally the responsibility of a Infrastructure Architect.  This is the last diagram of the three and will not be readily understandable by business users but familiar to solution architects and some developers.  The value is correct and accurate implementation including proper security implementation, and documentation for troubleshooting.

Further diagrams that many find to be truly useful include:

Sequence Diagram(s) — This illustrates the steps required to complete a process; you vertically list the components and use horizontal lines to show the interactions as steps (hence “sequence”) between the components with accompanying textual descriptions of the action taken.  For example, the exact steps and responsibilities of components for OAuth 2.0 using PKCE. This is one of the best diagrams to hand off to the software implementation team.

Systems Context Diagram / Context Diagram — shows the systems involved and excludes systems that are not. While the logical and conceptual diagrams could be familiar to business stakeholders, this is where this diagram is very useful for business user’s understanding.

Here are some useful vendor diagramming products

Lucid Charts — my go-to solution

Orbus Software — supports Conceptual, Logical, Physical diagrams (https://www.orbussoftware.com/enterprise-architecture/archimate/how-to-use-architecture-levels-effectively)

C4 model — for visualizing software architecture (modeling not diagraming, another approach) — https://c4model.com/

ArchiMate — model driven

MEGA — BPMN modeling

*** these products may evolve to support more capabilities.

To see how this fits into Agile methodology see — https://www.scaledagileframework.com/solution-intent/