The rise in installation/reinforcement and maintenance costs of power distribution systems enforces the planner to adopt an optimal strategy during system planning. The planning should be uch that the designed system should economically and reliably take care of spatial and temporal load growth, and service area expansion in the planning horizon. Mathematically, this planning is a multivariable multi-objective optimization problem. During the past decade or so, several planning algorithms have been developed. The purpose of this survey is to present a comprehensive review of all the developments in the planning technology, which includes all the reported optimization models and solution strategies. This state-of-the art survey is systematically organized to serve as a stepping stone for future researchers as well as a planning guide for the engineers. The various planning models are grouped in a three-level classification structure starting with two broad categories, i.e., planning without and with reliability considerations. The tree grows further with subdivisions. The last level of this classification tree consists of different planning models and solution strategies. Comprehensive discussions on each planning model are presented. © 2013 Springer-Verlag Berlin Heidelberg.