PROFIT EVALUATION OF A 2-UNIT SYSTEM WITH INTERNAL AND EXTERNAL REPAIRS, INSPECTION AND POST REPAIR

In practice, systems do not always fail with a major breakdown, needin g a heavy repair from some external source. Quite often, systems have a minor fault for which an immediate internal repair is more appropria te, in terms of availability of the system and economy, than calling a repairman from some external repair facility, waiting idly for his ar rival or making a call with a higher cost. The present work discusses two non-identical unit systems with two types of repair, the internal and the external one. The external repair is called only when the inte rnal staff fail to do the job. In the case of external repair, there i s a provision of inspection, wherein if the repair is found unsatisfac tory, it is sent for post repair. Using the regenerative point techniq ue, various reliability characteristics of system effectiveness have b een obtained.