Posts

In this post, we will explore the mathematical significance of a measurand. SAE AS6969™ follows JCGM 100 in defining a measurand as a particular quantity subject to measurement. In the Unified Modeling Language (UML) we would express a measurand in the form ‘Aircraft:: grossWeight: Mass’ where ‘Aircraft’ is a type that owns the property of […]

We are often concerned with three kinds of data model. The first kind is the conceptual data model (CDM). In a conceptual model, the instances of classes are entities in the real world; for example, real robots, real payloads, real tasks, real environments. In the CDM, we are concerned with definitional properties of these entities, […]

Part 1 of this post focused on the structural relationship between information elements. It discussed how a well-formed data model must reflect the ontology of the information that is processed and exchanged including its principal modalities, how messages are projections from the data model, how subject matter can be organized into layers of entity-relationship models […]

This post discusses data modeling – a branch of model based engineering (MBE) that has gained traction in the last few years.  A data model formalizes the semantics (i.e. the meaning) of the information to be processed and exchanged by a system. As with all branches of MBE, the initial investment in the model supports […]