Quantitative Engineering is a consequence of the ideas behind various flavors of Digital Engineering, Digital Twins, Digital Threads etc. while many think of specific numbers as quantities, this concept in OpenMBEE focuses more generally on the ability to represent and solve Engineering Problems with systematically and mathematically represented models of Systems and associated apps, platforms and capabilities . It is the presence of these representations along with the capability to integrate, package and distribute them without loss of access to the ability to resolve the systematic behavior and mathematical resolvability that seeks to make the distinction between qualitative engineering which can include specific quantities, and the existence of the complete representation of the system or product in a manor that all the relationships structure and behavior are countable and measurable.
This is not intended to diminish the value of Qualitative Engineering work, but rather to identify the value of both approaches and provide continuity of application in the methods of development.
Software Defined Systems
Software Defined Systems is a concept that occurs as an abstraction of the work done by @Robert Karban in the Open Source TMT Model. There are other inspirations such as Software Defined Radios, Software Defined Vehicles etc.
The general concept of Software Defined Systems is an approach that implements the ideas of Digital Twins, Threads etc with a more targeted approach that brings along Quantitative Engineering.