1. A method for decreasing a failure rate of each asset of a set of assets comprising: receiving, at a programmed hardware processor, data regarding an asset, said data including a failure rate function capturing a condition of said asset up to a point in time, a cost of preventative maintenance (PM) of said asset, a cost of an asset failure, and a cost of replacing an asset; receiving, at said programmed hardware processor, a further input specifying a time horizon; determining, at said programmed hardware processor, whether there is a need to replace said asset, and when a replacement of said asset is needed: computing, at said programmed hardware processor, a mean cost-rate optimization problem formulated as an objective function of a total cost of the asset over said specified time horizon, said total cost being a function of a cost of preventative maintenance (PM) of said asset for K−1 PMs, and an expected cost of repairs for an asset failure computed as a function of said failure rate function, and the cost of replacing an asset; computing, using the programmed hardware processor, an optimal number of preventative maintenance actions K and time intervals t k for each asset independently by minimizing said objective function with respect to an age of the electrical asset y k , where k represents a k th PM, wherein said schedule is formed without considering a labor and budget resource constraint; and the programmed hardware processor device further storing said optimal number of preventative maintenance time intervals for each asset as data in a memory storage device operatively coupled with said processor device; and the programmed hardware processor device generating a final maintenance schedule for the system of assets based on stored said optimal number of preventative maintenance time intervals by minimizing a deviation from the computed optimal PM time intervals subject to the labor and budget resource constraints.