Harness Engineering and SimpleModeling
Harness Engineering is an essential foundation in the AI era.While AI accelerates code generation, it also introduces structural instability and missing quality attributes. To control this, constraints and guarantees must be provided at the execution layer.
SimpleModeling connects BoK (Body of Knowledge), DSL (Domain Specific Language), and the execution platform into a single flow, providing a Harness that governs execution based on meaning. As a result, developers can focus on domain logic while maintaining consistent quality and reproducibility—even with AI-generated code.
Essence of Harness Engineering
Harness Engineering is an approach in which applications are executed through a controlled execution layer (the Harness), ensuring quality, reproducibility, and safety.
Its essence lies in executing software through a constrained environment rather than running it directly. On top of platforms provided by DevOps and Platform Engineering, it defines how execution is performed and ensures consistent quality.
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Centralize quality attributes in the framework
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Ensure reproducibility and safety
In environments where AI-generated code is prevalent, structure and quality attributes tend to be implicit, so constraints and guarantees at the execution layer are essential. Harness Engineering provides the foundation to control this instability and run generated code safely and consistently.
Extension by BoK
Traditional Harness Engineering primarily targets execution and operations. SimpleModeling extends this scope by introducing BoK.
Management of Meaning
BoK organizes concepts, relationships, and contexts into a structured knowledge base, allowing systems to be treated as meaning-rich structures rather than mere collections of code.
Integration with AI
BoK serves as a reasoning foundation for AI, enabling more accurate specification and code generation.
With this extension, the Harness evolves beyond execution control into a foundation that handles meaning.
Concept of Executable Harness
What SimpleModeling introduces is not just an extension of Harness Engineering, but a Harness as a predefined execution framework where domain structure and quality attributes are fixed.
In traditional development, domain structure, execution mechanisms, and quality attributes are not clearly separated, and in practice must be designed and implemented as a single whole. Experienced developers can consciously separate these concerns, but otherwise they tend to become entangled, resulting in complex and unstable implementations. AI-generated code shows a similar tendency toward such entangled structures.
SimpleModeling addresses this by clearly separating and fixing concerns: domain structure is defined by DSLs and model compilers, and quality attributes are handled by the execution platform (CNCF).
As a result, developers no longer need to manage structure and quality attributes themselves, and can focus on implementing domain logic.
This "execution framework with fixed structure and quality" is the essence of the Executable Harness. It can be seen as realizing Harness Engineering at the structural level.
Conclusion
While highly compatible with Harness Engineering, SimpleModeling extends its scope to include meaning itself. It is not just an execution platform, but a development foundation that treats meaning, specification, and execution as a unified whole. This approach allows developers to focus on domain logic while ensuring stable quality and reproducibility across the entire system, including AI-generated code. It represents a new foundational model for software development in the AI era.
References
Glossary
- BoK (Body of Knowledge)
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At SimpleModeling, the core knowledge system for contextual sharing is called the BoK (Body of Knowledge). The goal of building a BoK is to enable knowledge sharing, education, AI support, automation, and decision-making assistance.
- DSL (Domain Specific Language)
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A DSL (Domain-Specific Language) is a language designed for a particular domain, enabling direct and concise expression of the domain’s concepts and structures. Compared to general-purpose programming languages (GPLs), DSLs offer a higher level of abstraction tailored for domain-specific problem solving and automation.
- SimpleModeling
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SimpleModeling is a modeling-centered software development methodology and technology system for constructing a Domain Model from Knowledge, formalizing it in CML, realizing it as executable software through Cozy and AI, and running it on Textus.
- Quality Attribute
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A Quality Attribute is a characteristic that expresses the degree of quality with which software satisfies requirements in addition to performing its functions. Examples include Security, Performance, Availability, Reliability, Resilience, Observability, and Maintainability.
- Constraint
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In UML, a Constraint is a condition or restriction expressed in natural language or a machine-readable language to declare part of the Semantics of one or more Model Elements. Its evaluation yields a Boolean value and has no side effects.
- Platform
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A Platform is a shared set of technical foundations and services used to build, deploy, execute, and operate software.
- Model
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A Model is an abstraction that represents a subject according to a particular Purpose and Concern so that it can be understood, reasoned about, evaluated, or constructed. It is not the subject itself; it preserves the elements, relationships, and meanings required for its purpose.
- Literate Model
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Undefined
- CML (Cozy Modeling Language)
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CML (Cozy Modeling Language) is the SimpleModeling formal modeling language for describing the Executable Model portion of an Object Model that connects to program generation and execution.
- Cozy
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Cozy is the SimpleModeling toolchain that analyzes Models expressed in CML and other DSLs and transforms them into realization artifacts such as programs, configuration, and documentation.
- Cloud Native Component Framework (CNCF)
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Cloud Native Component Framework (CNCF) is a framework for executing cloud application components using a single, consistent execution model. Centered on the structure of Component, Service, and Operation, it enables the same Operation to be reused across different execution forms such as command, server (REST / OpenAPI), client, and script. By centralizing quality attributes required for cloud applications—such as logging, error handling, configuration, and deployment—within the framework, components can focus on implementing domain logic. CNCF is designed as an execution foundation for literate model-driven development and AI-assisted development, separating what is executed from how it is invoked.
- Execution Control
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Undefined