Strategic planning is a management activity and a process that defines the direction and the objective of an organization over the long term (what should the firm do on the long run?) and that defines how should resources should be allocated to pursue this objectives.
Strategic planning refers to develop a plan of action to achieve a particular goal. It includes an evaluation of the organization and the context. It has a focus on the future. It serves as a guide to allocate resources over the long run, but also as a guide to middle manager.
Taken as an ongoing process, it strategic planning can be a key asset of an organization.