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Architecture¤

"The Architecture view defines the fundamental characteristics of each component and its relationship with the system and other components, including shape, position, and interfaces."3

Architecture is the anchor view in ADH. Before we ask what a thing must do, how well it performs, or how it behaves off design, we need to say what the thing is and where it sits in the aircraft.23

What Architecture Means In ADH¤

The paper-first model is straightforward. Architecture is the parent view. Requirements, Performance, and Behavior derive from it and stay traceable back to it.2 The abstract makes the same point in plainer engineering language when it says ADH exchanges "geometry definitions, disciplinary tool inputs/outputs, and engineering requirements" through one central structure.1

In the current code, the base Architecture model inherits shared node metadata and then adds its WBS identifier.4

  • name
  • description
  • source_info
  • uuid
  • wbs_no

That is a deliberately small core. The richer subclasses add domain content on top of it. For example, Component adds geometry, parameters, and subcomponents; System adds parameters, diagram, and subsystems; Propulsion adds geometry, cycle, and parameters.679

What The Base Model Actually Enforces¤

The current implementation uses Architecture only for true architecture-view nodes in the WBS hierarchy.4 Two details matter in practice.

First, wbs_no is a string, not an integer and not a free-form label. The validator enforces a dotted numeric pattern such as 1.2.2.3.4 That keeps the serialised tree aligned with MIL-STD-881-style numbering.

Second, source_info sits on the architecture node itself through the shared node metadata mixin.5 That means the structural definition can carry authorship, dates, versioning, and external references before any child view appears. It is a pragmatic choice. Engineers usually know where geometry or configuration data came from long before they know every requirement or every off-design table.

Third, every remaining architecture node also carries optional requirements, performance, and behavior child views through MSoSAMixin.4 That is the recursive MSoSA rule the cleanup restored across both hand-maintained and generated WBS nodes.

Usage Example¤

The simplest way to see the Architecture view is to instantiate a WBS node that only carries architectural data. A generated Wing node works well for that because, in the current repository, it is a light Architecture subclass with a fixed WBS number.11

from adh.msosa.metadata import Author, SourceInfo
from adh.wbs import Wing

wing = Wing(
    name="Main Wing",
    description="Reference lifting surface for the baseline aircraft",
    source_info=SourceInfo(
        authors=[Author(name="Example Analyst", organisation="ADH Docs")],
        version="0.1.0",
    ),
)

{
  "name": "Main Wing",
  "description": "Reference lifting surface for the baseline aircraft",
  "wbs_no": "1.2.2.3",
  "source_info": {
    "authors": [
      {
        "name": "Example Analyst",
        "organisation": "ADH Docs"
      }
    ],
    "version": "0.1.0"
  }
}

Current Implementation Notes¤

The paper presents Architecture as the universal parent view for every recursive WBS node.2 The repository now follows that rule directly: if a class still inherits Architecture, it also inherits MSoSAMixin.

Generated taxonomy nodes such as Wing, Fuselage, and AircraftSystem express hierarchy, WBS numbering, and the recursive MSoSA child views.1011 Richer domain classes such as Component, System, Equipment, and the hand-maintained Propulsion class add the fields that make an architecture node useful in day-to-day modelling.6789

The cleanup also removed several long-standing misuses. Helper geometry models, scalar wrappers, and solver-support models no longer inherit Architecture; they now live as plain supporting models instead.

  1. Engelbeck et al., Model-Based Systems Analysis and Engineering: Aircraft Data Hierarchy, NASA/CR-20250007045, Abstract: "The ADH facilitates efficient exchange of critical information-geometry definitions, disciplinary tool inputs/outputs, and engineering requirements-through a centralized, validatable data structure..." ↩

  2. Engelbeck et al., NASA/CR-20250007045, Section 10.4: "The ADH aligns with the Model-Based System-of-Systems Architecture (MSoSA) guidelines defined in Figure 12, which defines a hierarchical structure with the Architecture view as the parent and Requirements, Performance, and Behavior as child views." ↩↩↩

  3. Engelbeck et al., NASA/CR-20250007045, Section 10.4: "The Architecture view defines the fundamental characteristics of each component and its relationship with the system and other components, including shape, position, and interfaces." ↩↩

  4. Current implementation: src/adh/msosa/architecture.py. ↩↩↩↩

  5. Current implementation: src/adh/msosa/metadata.py. ↩

  6. Current implementation: src/adh/wbs/airframe/airframe.py. ↩↩

  7. Current implementation: src/adh/wbs/systems/systems.py. ↩↩

  8. Current implementation: src/adh/wbs/equipment.py. ↩

  9. Current implementation: src/adh/wbs/propulsion/propulsion.py. ↩↩

  10. Current implementation: src/adh/wbs/air_vehicle.py defines the nested WBS tree for AircraftSystem, AirVehicle, Airframe, and other taxonomy nodes. ↩

  11. Current implementation: src/adh/wbs/air_vehicle.py defines Wing as a direct Architecture subclass with wbs_no="1.2.2.3". ↩↩