%0 Journal Article %A F. Urem and K. Fertalj and I. Livaja %D 2011 %J International Journal of Economics and Management Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 59, 2011 %T The Impact of Upgrades on ERP System Reliability %U https://publications.waset.org/pdf/14351 %V 59 %X Constant upgrading of Enterprise Resource Planning (ERP) systems is necessary, but can cause new defects. This paper attempts to model the likelihood of defects after completed upgrades with Weibull defect probability density function (PDF). A case study is presented analyzing data of recorded defects obtained for one ERP subsystem. The trends are observed for the value of the parameters relevant to the proposed statistical Weibull distribution for a given one year period. As a result, the ability to predict the appearance of defects after the next upgrade is described. %P 1492 - 1496