This document provides an overview of planning theory and approaches to managing development. It discusses classical planning models and their limitations, as well as emerging approaches since the 1970s that focus more on participation, social learning, and flexibility. Some key points covered include: classical planning aimed to be rational but made unrealistic assumptions; "blueprint" planning faced challenges in complex environments; projects and sector-wide approaches replaced comprehensive planning; and newer paradigms emphasize sharing responsibility, decentralization, and an ongoing process of learning and adaptation.