Backcasting & Pathway Analysis

Reasoning backwards from a desired future to identify viable routes to it.

Several sequenced routes reaching one specified future Three routes leave the present and converge on a single ringed destination at the right, each carrying milestones at different points along its length, so the routes differ in sequence rather than only in shape. A fourth dashed route leaves the present and stops short of the destination: the pathway of doing nothing.

At a glance

Produces
A sequenced route from a specified future back to the decisions available now.
Depends on
A target specified precisely enough to reason backwards from - and contested in the open.
Fails when
The destination is left vague, which makes every pathway look feasible.

Backcasting begins with a specified future condition and reasons backwards to the present, identifying the sequence of changes that would be required to reach it. Pathway analysis then compares the alternative routes and examines their feasibility, timing, dependencies and trade-offs.

How we approach it

Backcasting is useful precisely when extrapolation is not, because the desired outcome is discontinuous with current trends.

  • The target future is specified carefully and contested openly. A vague destination produces vague pathways.
  • We map dependencies rather than lists. Ordering matters: many plausible pathways fail because steps were placed in an infeasible sequence.
  • Constraints are treated as variables. Part of the value of the exercise is identifying which constraints would have to move, and who could move them.
  • Pathways are compared against each other, including against the pathway of doing nothing, which is often under-examined.