A model is developed for use by logistics planners in determining period by period maintenance requirements for repairable item populations. The model generates maintenance requirements with respect to manpower and facility requirements and spare parts requirements. The model is capable of capturing nonsteady-state failure behavior of populations of repairable items. Each item within the population is broken down into one or more families of components and subcomponents that can have different failure/repair characteristics. Probability of component failure may be generally distributed. A specific data requirement for the model is established. The model is structured to allow the user to conduct various"what if gaming" through an iterative procedure on a personal computer. This research document includes a literature review that establishes a history of logistics modeling. The literature review provides impetus to the proposed research by defining a need for a transient state model for maintenance requirements planning. The model is validated by a case study involving the generation of maintenance requirements for a case population. / Master of Science