Scenario Background

Forecast vs. Backcast

There is a useful, broad classification of scenario exercises: whether they are a forecast or a backcast. While both procedures have a similar end product - a future state and a path to reach it - the process for generating the product is very different.

  • A starts with the current situation and possible future paths, then deduces an end-state.
  • A starts with the current situation and an end-state and then deduces possible future paths.

In a backcast, there is usually some judgement about the desirability of the future state. Because of this, backcasts are sometimes called normative scenarios, while forecasts are sometimes called descriptive or exploratory scenarios.