P1547.7 is part of the IEEE 1547 series of standards. Whereas IEEE Std 1547-2003 provides mandatory requirements for the interconnection of distributed resources (DR) with electric power systems (EPS), this guide does not presume the interconnection is 1547 compliant. Further, this guide does not interpret IEEE Std 1547 or other standards in the IEEE Std 1547 series and this guide does not provide additional requirements or recommended practices related to the other IEEE Std 1547 documents. However, DR interconnection may contribute to resultant conditions that could exceed what was normally planned for and built into the distribution system. This P1547.7 guide provides alternative approaches and good practices for engineering studies of the potential impacts of a DR or aggregate DR interconnected to the electric power distribution system. This guide describes criteria, scope, and extent for those engineering studies. Study scope and extent are described as functions of identifiable characteristics of the DR, the EPS, and the interconnection. The intent includes promoting impact study consistency while helping identify only those studies that should be performed based on technically transparent criteria for the DR interconnection.