graph TD A[Digital Engineering] --> B[MBSE] A[Digital Engineering] --> C[MBE] A[Digital Engineering] --> D[Digital Thread] B[MBSE] --> E[SysML Models] C[MBE] --> F[FEA, CFD, SPICE] D[Digital Thread] --> G[Data Flow Across Lifecycle] A[Digital Engineering] --> H[DEFII Framework] H[DEFII] --> I[Ontology-Aligned Data] H[DEFII] --> J[Automated Reasoning] H[DEFII] --> K[Tool Proxy Interfaces] |=== == Position in Knowledge Hierarchy *Broader concepts:* - Part I (is-a) *Narrower concepts:* - MBSE (is-a) - MBE (is-a) - DE Ecosystem (part-of) == Details Digital Engineering transforms how engineering work is conducted by creating a connected environment where information flows seamlessly across disciplines and throughout the system lifecycle. It addresses the key challenges that have historically plagued complex engineering projects: * *Stove-piped analysis*: Traditional engineering approaches often involve separate teams working in isolation with little communication between disciplines * *Data silos*: Information is stored in different formats across various tools without a unified way to access or integrate it * *Inconsistent interpretations*: Different teams may interpret the same data differently, leading to errors and rework The core innovation of Digital Engineering is its use of ontologies to formalize the underlying information model. Unlike traditional schemas or databases, ontologies provide a rich semantic layer that enables: * *Interoperability*: Data can be shared across different tools and domains * *Reasoning*: Systems can automatically infer new knowledge from existing data * *Consistency*: Ensures data adheres to defined rules and constraints [CAUTION] icon:warning[] Digital Engineering is not simply about digitizing existing processes—it requires a fundamental shift in how engineering organizations operate, including new workflows, collaboration practices, and cultural changes. === Ontology-Aligned Data: The Foundation The foundation of Digital Engineering is ontology-aligned data. This means that data is structured according to formal ontologies that define the concepts, relationships, and rules for a specific domain. For example, in the armaments domain, an ontology might define concepts like "missile," "warhead," "propulsion system," and relationships like "hasPart" or "affects." This ontology alignment enables: * *Common vocabulary*: All stakeholders use the same terms to describe the same concepts * *Machine readability*: Systems can understand the meaning of data, not just the format * *Interoperability*: Data can flow between different tools without manual translation [NOTE] icon:book[] The Armaments Interoperability and Integration Framework (IoIF) is a specific implementation of Digital Engineering that uses ontologies to integrate models across disciplines, as demonstrated in the Catapult case study. === Tool Proxy Interfaces: Connecting the Ecosystem The DEFII framework specifies three categories of interfaces for connecting engineering tools to the ontology-aligned data repository: [cols="1,2"] |=== |Interface Type |Description |Direct Interface |Uses standards like SPARQL to query and update data directly in the repository |Mapping Interface |Translates data from tool-specific formats into ontology-aligned representations |Specified Model Interface |Uses standardized model descriptions to access ontology-aligned data |=== These interfaces allow Digital Engineering to work with existing tools rather than requiring complete replacement of established engineering workflows. [IMPORTANT] The beauty of Digital Engineering is that it hides the complexity of ontologies from typical users. Engineers continue to work in familiar tools like SysML, while the underlying ontology handles the interoperability. == Practical applications and examples Digital Engineering is being implemented across various domains to solve complex engineering challenges. Here are some practical examples from the context: === Catapult Case Study The Catapult example demonstrates how Digital Engineering enables integrated analysis across multiple disciplines: 1. *Mission model*: Defines the objective (e.g., "hit a target at a specific distance") 2. *System model*: Describes the catapult system (e.g., arm length, spring constant) 3. *Analysis models*: Include physics-based simulations (e.g., ballistics, geometry) 4. *Assessment Flow Diagram (AFD)*: Explicitly describes relationships between parameters and interfaces for different simulations The IoIF workflow coordinates these elements, pulling data from SysML models, running simulations, and visualizing results in dashboards. This enables engineers to quickly explore trade-offs between different design parameters. [NOTE] icon:lightbulb[] In the Catapult example, the AFD is a SysML parametric diagram that models the relationships between parameters (e.g., spring constant, launch angle) and the resulting performance metrics (e.g., range, accuracy). === Armaments Interoperability and Integration Framework (IoIF) IoIF is a specific implementation of Digital Engineering that has been successfully used in military applications. It demonstrates how ontologies can be used to integrate models across different domains: * *Mission analysis*: Models mission objectives and measures * *System analysis*: Models system components and their relationships * *Discipline-specific analysis*: Integrates FEA, CFD, and other simulation tools * *Decision support*: Visualizes trade-offs using dashboards The IoIF workflow shown in Figure 9 (from the context) demonstrates how data flows between tools like Creo (for geometry modeling), Python (for simulation), and MATLAB (for ballistic analysis), all coordinated through the ontology-aligned repository. [NOTE] icon:info[] IoIF uses a central repository (triplestore) to hold ontology-aligned data, which allows different tools to exchange information without requiring direct integration between them. == Related wiki pages link:MBSE.html[Model-Based Systems Engineering] + link:MBE.html[Model-Based Engineering] + link:DEFII.html[Digital Engineering Framework for Integration and Interoperability] + link:Digital%20Thread.html[Digital Thread] + link:Ontology.html[Ontology] + link:IoIF.html[Armaments Interoperability and Integration Framework] + link:Catapult%20Example.html[Catapult Case Study] + == References link:https://www.dod.mil/Portals/1/Documents/pubs/2018-02-13_Digital_Engineering_Strategy.pdf[Department of Defense Digital Engineering Strategy] + link:https://www.w3.org/TR/owl2-overview/[OWL 2 Web Ontology Language] + link:https://www.omg.org/sysml/[SysML Standard] + link:https://protegewiki.stanford.edu/wiki/Main_Page[Protégé Ontology Editor] + link:https://arxiv.org/abs/2206.10454[Digital Engineering Framework for Integration and Interoperability] + link:https://www.w3.org/TR/rdf-concepts/[RDF Concepts and Abstract Syntax] + link:https://www.w3.org/TR/sparql11-query/[SPARQL Query Language] + == icon:project-diagram[] Digital Engineering Ecosystem Visualize the relationships within the Digital Engineering ecosystem [mermaid]