International Science Community Association Research Journal of Recent Sciences 2277 - 2502 1 4 2012 April 2 Machine Repair Problem with Spares and N-Policy Vacation 72 78 EN Pascal C. 1 Laboratoire d’Etude et de Recherche en Chimie Appiquée (LERCA), Ecoe Poytechnique d'Abomey-Calavi (EPAC), Universit� d'Abomey-Calavi (UAC), 01 BP 2009 Cotonou, REPUBLIC OF BENIN Agbangnan D. 2 Institut Pluridisciplinaire de Recherche sur l�Environnement et les Mat�riaux (IPREM), Universit� de Pau et des Pays de l�Adour (UPPA), UMR 5254 Technopole H�lioparc, 2 avenue du pr�sident d�Angot 64053 PAU Cedex, FRANCE Christine Tachon 3 Institut des Sciences Mol�culaires (ISM), Universit� de Bordeaux 1, CNRS UMR 5255 Batiment A12, 351 cours de la lib�ration, 33405TALENCE cedex, FRANCE Justine Dangou 4 Anna Chrostowska 5 Fouquet Eric 6 DominiqueC.K. Sohounhloue 7 Srivastava K.P. 1 Ganga Singh College, Jai Prakash University, Chapra-841 301, Bihar, INDIA Singh VikashKumar 2 Balamuralitharan S. 1 Department of Mathematics, Sri Ramanujar Engineering College, Chennai-48, INDIA Rajasekaran S. 2 Professor and COE, Department of Mathematics, BS Abdur Rahman University, Chennai-48, INDIA Nwajei G.E. 1 Dept. of Chemistry, Delta State University Abraka, NIGERIA Okwagi P. 2 Dept. of Chemistry, College of Education Agbor, NIGERIA Nwajei R.I. 3 Dept. of Botany, Delta State University, Abraka, NIGERIA Obi-Iyeke G.E. 4 Yousefi Z 1 Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, IRAN VefaAkpinar M. 2 Civil Engineering Department, Karadeniz Technical University, Trabzon, TURKEY AntonyRavindran A. 1 Manonmaniam Sundaranar University, Dept. of Geology, Geophysical Research Lab, V.O. Chidambaram College, Thoothukudi, INDIA PebamNganthoiba Mangang 1 School of Social Work, Tata Institute of Social Sciences, Mumbai-400088, INDIA Abbasian S. 1 Faculty of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, IRAN Attarzadeh S.R. 2 Faculty of Physical Education and Sport Sciences, Shahid Montazeri University of Mashhad, Mashhad, IRAN Darzabi T. 3 Momeni M. 4 Dev Nikhil 1 YMCA University of Science and Technology, Faridabad, Haryana, INDIA Attri Rajesh 2 Gateway Institute of Engineering and Technology, Sonipat, Haryana, INDIA Mittal Vijay 3 University Institute of Engineering and Technology, M.D. University Rohtak, Haryana, INDIA Kumar Sandeep 4 Mohit 5 Satyapal 6 Kumar Pardeep 7 Motegaonkar ManoramaB. 1 Azad College Ausa, MS, INDIA SalunkeShridar D. 2 Rajarshi Shahu College, Latur, MS, INDIA Amanchi NageswaraRao 1 Protozoology and Environmental Toxicology Unit, Department of Zoology Nizam College, Osmania University, Hyderabad, INDIA Mohd.Masood Hussain 2 Bhatt TarunKumar 1 Department of Biotechnology, Central University of Rajasthan, Kishangarh, INDIA Sharma D.C. 1 School of Mathematics, Statistics and Computational Sciences Central University of Rajasthan, Kishangarh Ajmer, INDIA > Review Paper 2012 2 13 2012 April 2 In this paper we have taken a machine repairable system with spares and two repairmen where “the partial server vacation” is applied. In our system, the first repairman never takes vacations and always available for serving the failed units. The second repairman goes to vacation of random length when number of failed units is less than N. At the end of vacation period, this repairman returns back if there are N or more failed units/machine accumulated in the system. Otherwise this repairman goes for another vacation. Vacation time is exponentially distributed. By using of Markov process theory, we develop the steady state probabilities equations using transition diagram and solve these equations recursively. We present derivations of some queuing and reliability measures. A cost model is developed to determine the optimum value of N while the system availability is maintained at certain level. Sensitivity analysis is also investigated. In this paper we not only analyze the queuing problems but also analyze the reliability characteristics of the system. Copyright@ International Science Community Association