Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Partial element equivalent circuit method (PEEC) is partial inductance calculation used for interconnect problems from early 1970s which is used for numerical modeling of electromagnetic (EM) properties. The transition from a design tool to the full wave method involves the capacitance representation, the inclusion of time retardation and the dielectric formulation. The main research activity in this area has been and are performed, by Albert Ruehli at IBM Thomas J. Watson Research Center, starting with a publication in 1972. At that time the foundation of the PEEC method was presented, i.e. the calculation of the partial inductances. The PEEC method was extended to more generalized problems, including dielectric material and retardation effect.