In order to remain competitive, organizations are reviewing their operations to determine ways to reduce their operating and maintenance costs. It has been estimated that the costs associated with equipment failures and malfunctions in the mobile fluid power industry in the United States reaches billions of dollars each year.It has been reported that contamination accounts for 70% of equipment failures, and this is an area where substantial savings can be made. system reliability is directly related to the amount of contamination in the system and improvements can only be made by having improved fluid cleanliness levels brought about by correctly applied and specified filters.This paper presents the necessity for manufacturers and users to develop a “Total Cleanliness Control” program. This program addresses equipment requirements for a specified level of cleanliness of components ranging from the initial fabrication stages through to in-service operation.Fundamental to achieving the desired fluid cleanliness level, is the selection of the most appropriate filter for a given application. In view of the importance of the filter, this paper also reviews the major facets of filter element design and construction and how all current ISO testing standards must be used to verify performance claims.Finally, this paper addresses the operational and maintenance cost factors associated with component and fluid maintenance. Economic benefits derived from achieving a high degree of system cleanliness are dependent on various factors of operation and maintenance. Specific areas including setting cleanliness standards, instituting effective filter performance evaluations, evaluating filter vendor supply agreements, and having aftermarket technical support are discussed to identify areas for equipment manufacturers and end users of equipment to save money.