A key point in considering strategic planning is that it is not forecasting. The future is unpredictable and is not a product of the past. This low opinion of forecasting has gained in influence recently. But such an approach creates a dilemma for the strategic planner. He needs to take into account potential future forces--but he can only do this with inadequate means. Forecasting methods, however, can suggest trends and it is possible to reduce the number of possible futures to a manageable number. This is, in effect, creating scenarios. The concept of using alternative scenarios in planning was popularized some 20 years back. The proviso was made that they should not be interpreted as forecasts. The methods have proved highly flexible and include the consensus technique, the iteration-through-synopsis technique, and the cross-impact method. Various studies using one or more of these have been implemented, perhaps the best known being by Meadows and by Mesarovic. These have been based on the so-called 'hard' method, using computers. 'Soft' methods are based more on the mind and use psychology and sociology, the most familiar being the Delphi method. A somewhat more sophisticated version is Cross-Impact Analysis.