Journals / Communications Faculty of Sciences University of Ankara Series A1: Mathematics and Statistics / 2014 / Cilt: 63 - Sayı: 1
INVESTIGATION OF TREND BY GRAPHICAL METHODS IN COUNTING PROCESSES
- Journal
- Communications Faculty of Sciences University of Ankara Series A1: Mathematics and Statistics
- Pages
- 73–83
- DOI
- —
Abstract
Abstract. A data set fX1; X2 ; :::; Xng comes from a counting process in many of maintenance, repair and replacement problems commonly includes systematical changes. Systematical changes in the data set indicate a trend which suggests that X1 ; X2 ; :::; Xn are not identically distributed. In this case renewal process cannot be used as a model. In modelling of a data set the existence of a trend has to be searched ...rstly. A simple way to detect a trend is to apply a graphical method. In this study the cumulative number of failures versus the cumulative time plot, estimating the rate of occurrence of failures in successive time periods plot, Nelson-Aalen plot and the total time on test plot will be described and evaluated on three real data sets.