A series of posts about those things. Oldest posts first.

Resources, Events, and Agents (REA)

This is one of the two basic patterns of Valueflows.

This will be a quick overview of REA. Here are a lot of references explaining the history and development of this pattern: https://www.valueflo.ws/appendix/rea/

The main concepts of REA:

REA main concepts

An EconomicEvent generally includes one type of EconomicResource (which might be a lot of the same ResourceSpecification) and two EconomicAgents. In a Transfer EconomicEvent, one Agent gives the EconomicResource or Resources to another Agent. In a Transformation, which ValueFlows calls a Process, one Agent provides some EconomicResources as inputs and either the same or a different Agent takes some transformed Resources as outputs. (A Process will almost always have at least two EconomicEvents, an input and and output, and often several more inputs and sometimes more outputs.)

Duality is an abstract concept that basically means “why did the Agent give up those Resources”. In a Transfer, it might be to get some other Resources in exchange from the other Agent. In a Transformation, it is to get an improved or different Resource as an output of the Process.

REA defines three different levels of similar concepts:

REA levels

Those are the Valueflows (VF) names for the concepts. In the REA references linked above, you will see different names;

VF:Recipe and VF:ProcessSpecification do not exist (yet) in REA literature.