Maintenance management is a less explored area compared to other fields of management. Since, it has gained the acceptance as a profit contributor and the status of being a partner with the production, the area has recently attracted more research. The present book has made an attempt to bridge a very important gap in the field of maintenance management by conducting a systematic review of all the published literature and identify gaps. Out of many gaps reported in the literature survey, comparatively less explored area of MERIS has been addressed in this work. These systems are gaining increased importance as more and more equipment are getting modular in construction and their repair/replacements are being undertaken in multiple echelons with repair/replacements facilities. Gaps in the MERIS are identified and modeling framework has been suggested. Some of the models in the framework have been developed and tested by actual implementation in the maintenance organization. This has been a very important contribution of the study wherein an action research (AR) based approach has been used either to develop models or to validate the developed models.