A discrete-event system is controlled by a set of n local supervisors under decentralized supervision. Some local supervisors may be redundant in the sense that eliminating these local supervisors does not have an effect on the generated language. If the local supervisors are reliable, then we can reduce the cost of implementing supervisors by minimizing the set of local supervisors. Motivated by this, we present an algorithm to minimize the set of local supervisors by eliminating redundant ones in fully decentralized supervision proposed by Kozak and Wonham.