A variable property is a property of an Exchange that is included as a variable in a mathematical relation of another exchange within the same dataset. This concept is fundamental to establishing dynamic relationships between different exchanges in Life Cycle Assessment data modelling.
In LCA databases, exchanges within an activity dataset often have interdependencies that need to be mathematically expressed. A variable property allows one exchange's characteristics to influence the quantities or properties of other exchanges through mathematical formulas. This creates a flexible and responsive data structure where changes to one exchange automatically propagate through related exchanges according to the defined mathematical relationships.
For example, in an activity dataset representing electricity generation, the amount of fuel consumed (one exchange) might serve as a variable property in formulas that calculate the resulting emissions (other exchanges). The emissions are then mathematically linked to the fuel input, ensuring consistency and accuracy in the dataset. When the fuel input quantity changes, the emissions are automatically recalculated based on the mathematical relationship.
This approach is particularly valuable in creating parameterised datasets where multiple exchanges depend on common variables, enabling more efficient data management and reducing the risk of inconsistencies. By using variable properties, database developers can encode the fundamental relationships between exchanges, ensuring that datasets remain internally coherent even when specific values are updated or when datasets are adapted for different scenarios.
The use of variable properties supports both data quality and transparency, as the mathematical relationships between exchanges are explicitly documented within the dataset structure rather than being hidden in external calculations.
