Rising costs have increased the need for simplifying service. The response at Cummins Engine Company has been a program to improve the serviceability of engines, plus an effort to help equipment manufacturers make engines more serviceable in their installations. The program is a cooperative effort among several areas.Design criteria for improved engine serviceability are discussed. Key maintenance and repair operations are used as the basis for measuring and comparing the serviceability of engines. The method presented is flexible enough to allow various trade-offs to be made during the design stage.Guidelines for improved installation serviceability are outlined. The guidelines establish time limits for daily checks and routine maintenance, plus targets for service repairs. These are based on the times to perform the respective operations on free standing engines with allowances for installation considerations.