Carefully defining the time horizon of the Foresight exercise is essential:
- Different time horizons are suitable for different types of subjects. When the exercise is operating on a time horizon that does not match the dynamics of the subject it will not be useful
- For many of the formal methods that can be applied to support the Foresight exercise it is extremely important to be clear about the time horizon that is to be addressed. Without this information the methods cannot be applied adequately.
Criteria for defining the time horizon
The time horizon of a Foresight exercise should lie beyond the normal planning horizons of the players involved but close enough that it could still be influenced by today's decisions. In other words it should be far enough to allow changes to be possible but not so far away as to seem irrelevant.
This criterion depends very much on the sector. Within the public sector, the time horizon usually tends to vary from around 10 to 20 years. But in the case of infrastructures (like power stations, transport networks, etc.) the time horizon might be 30 to 50 years. Within the private sector, the normal planning is generally one generation of the product or service ahead, thus a good time horizon for corporate Foresight might be two generations of the products and services. Nobody is yet working on products and services two generations ahead, so whatever the outcome nobody's current work will be disrupted.
An exercise which is more action-oriented will tend to have a shorter time horizon. A 5-year time horizon tends to be used in technology-oriented exercise in fields where technologies are developing very quickly (e.g. Information & Communication Technologies).
An exercise which is more vision- or creativity-oriented will have a longer time horizon. A 20-year time horizon is necessary to take into account longer-term changes such as demography, social values, the rise or decline of economic powers, environmental degradation, global warming.
Other factors that should be taken into account when defining the time horizon:
- The inertia of the system and the need to blur the periodic effects that generate turbulence (which can lead to the system's being misunderstood);
- The schedule of decisions to be made, the power to decide and the means to be used (note that drafting a strategy is useless if the means to implement it are unavailable: for example if the investment budget is allotted for the next ten years, a ten year Foresight exercise is useless since there is no room for manoeuvre);
- The degree of rigidity and motivation of the players.
In the end, there is no secret recipe. Common sense and pragmatism are needed when choosing the optimal horizon.
There is more information on setting the time horizon in some of the example cases: