Ann Oper Res (2006) 143: 91–106 DOI 10.1007/s10479-006-7374-1 “Optimization of aircraft maintenance/support infrastructure using genetic algorithms—level of repair analysis” Haritha Saranga · U. Dinesh Kumar C  Springer Science + Business Media, Inc. 2006 Abstract Level of repair analysis (LORA) is an approach used during the design stage of complex equipment for analysis of the cost effectiveness of competing maintenance strategies. LORA is carried as a part of the life cycle cost and cost of ownership analysis and plays a significant role in minimizing the life cycle cost and cost of ownership of the capital equipment. Since many purchasing decisions of complex equipment are based on cost of ownership, it has become essential to carry out LORA to compete in the market. In this paper, we develop a mathematical model for LORA and propose a solution methodology based on genetic algorithms. The concept is illustrated using a hypothetical aircraft engine. Keywords Aircraft maintenance · Cost of ownership · Genetic algorithms · Level of repair analysis · Life cycle cost · Multi echelon · multi indenture From being a “necessary evil”, maintenance has become a strategic issue of equipment and asset management. Concepts such as Reliability Centered Maintenance (RCM), Total Productive Maintenance (TPM) and Business Centered Maintenance (BCM) all have the same objective of improving the productivity of the equipment through effective maintenance. Optimisation of maintenance tasks has attracted the attention of many researchers in the past few decades (Park, 1979; Jayabalan et al., 1992; Zhang et al., 1993; Makis et al., 1993). Many of these articles, however, deal with micro level issues related to maintenance such as optimal replacement time and optimal preventive maintenance intervals based on reliability and cost of repair, replacement etc. The secret of effective maintenance is not about the optimization of maintenance tasks during operation of the equipment, but optimization of maintenance and maintainability during the design stage of the equipment in order to achieve minimum life cycle cost (LCC) or minimum total cost of ownership (TCO). In fact all the LCC and TCO H. Saranga () Learning Resource Center, Indian School of Business, Gachibowli, Hyderabad, 500019, India e-mail: haritha saranga@isb.edu U. D. Kumar Indian Institute of Management Calcutta, India Springer