EAM.4:4.3 - Vary drivers and form coherent scenarios

For each material change, explain how it affects a component: more users, different use per user, a new industrial commitment, changed losses or a shared environmental condition. Apply that change to the appropriate base. For example, a 10% increase in household use changes the household component, not automatically the district’s losses and industrial use.

Combine component values that can obtain together. Several site maxima can occur at different hours; weather can also make formerly separate peaks coincide. Where timing matters, construct a common-period profile or obtain the applicable specialist account. Preserve location, service class and quality conditions that a total could conceal.

Form an unchanged-policy baseline before crediting a proposed demand-management measure. Describe a measure’s affected users, expected effect, delivery conditions and cost as an alternative for EAM.7. Use its reduction only in the scenario where those conditions hold. A proposed service reduction remains subject to the relevant authority.

Test the drivers that can change eligibility or preference. A justified range or a few explicit scenarios can be sufficient. If an option has 100 units of spare contribution, an uncertain additional demand spanning 90–170 leaves its adequacy unresolved; a range wholly above 100 establishes that this option cannot cover that demand range without another contribution. This threshold can identify a useful further inquiry. Give a scenario a probability only when evidence supports that interpretation.

A more elaborate forecast is needed when an important dependency, changing population or response to price, weather or restrictions cannot be supported by the simple account. Ask the specialist for the demand at the required boundary and periods, the relevant driver combinations, uncertainty and limitations. The receiving asset decision still compares the returned result under those conditions.