Weighted vs. unweighted

This option refers to whether or not the inputs to the modules are weighted by the scenario weightings before being ringfenced.

The "weighted" option means that the scenarios are weighted (or risked) before being ringfenced and subsequently back-allocated. If weighted is selected then the ringfenced module is calculated once based on a weighted average of the individual scenarios.

The "unweighted" option means that the scenarios are calculated independently or "in parallel". The scenario weightings are only applied at the final stage when reporting on the results.

This distinction is illustrated in the diagrams below.

Standard ringfencing weighted

Standard ringfencing unweighted