Along with forecasting, Strategic Planning is often considered one of the predecessors of Foresight.
Planning literally just means the creation of a plan, which is a proposed or intended method of getting from one set of circumstances to another, usually from the present situation, towards a desirable future situation. It is by definition a normative method.
Planning can refer to the planned economy such as the Soviet Union or the former Eastern European countries. Nowadays, the term is still widely used in the public and private sector, in relation to preparing for, or achieving, some future state, for instance planning for the use of land and related resources.
In the last few decades, long-term planning using inflexible blueprints has been discredited because of the growing awareness that high levels of uncertainty are the norm, not the exception, and that qualitative changes frequently invalidate the assumptions based upon quantitative change. Conversely, there has been a move from a "rational" approach aimed at achieving equilibrium and stability, to a more evolutionary approach.
Planning methods have been developed extensively in the last few decades. These are now extremely sophisticated, and able to work effectively in many contexts. But they tend to focus on shorter-term, more predictable topics than Foresight does. They also tend to take the objectives and aims of the eventual activities as givens, as ends for which we are seeking to define the most effective means. In contrast, Foresight may lead us to question the longer-term objectives that are being pursued, and is likely to deal with uncertainties that are sufficiently high to reduce the credibility of many restricted planning tools.
Some methods that have been employed in Foresight exercises for defining key actions and priorities include the analysis of critical/key technologies (the general principles behind this approach can be applied to things other than technologies) morphological analysis and relevance trees. SWOT analysis might also be seen as a planning method.