These pages cover the user manuals and knowledge base for Ratio Computer Aided Systems Engineering or Ratio for short.

Ratio focuses on the development of methods and tools for the specification, visualization, analysis, and optimization of system architectures to support engineers in avoiding rework and in developing even better systems. Ratio combines the latest innovative and scientific insights & high-end algorithms to ultimately boost the productivity of our clients and their partners.

These pages are dominated by documentation on the Elephant Specification Language – a formal language to write extremely structured system specifications. This language can be parsed and used to derive architectural models in the form of (derived) dependency networks. These provided an excellent basis for a digital-twin and Model Based Systems Engineering (MBSE) approach in general. Thus, bringing MBSE to the early design phase.

The remainder of these pages describes analysis methods that provide continuous insight in your system as your specifications grow over time.

User manuals

The User manuals pages focus on the application and use of our products.

Python package documentation

To make life a little bit easier we have created several Python Packages for handling, visualizing and analysing ESL specifications in particular and graphs in general. You can:

  • Check out the RaGraph Python Package Docs to create, manipulate, and analyse graphs consisting of nodes and edges that represent system architectures.

  • Check out the RaESL Python Package Docs to parse and compile ESL files, create various visualizations and generate PDF documents.


These Reference documentation pages focus on the scientific and mathematical foundations and expansion of our products.

Background information

The Bibliography page contain plenty references for a more thorough background reading on Systems Engineering in general and to the different employed methods and algorithms at Ratio.