An exploratory analysis of system test data

We conduct an exploratory data analysis of a specific system test data set that includes concomitant variables measuring aspects of test effort as well as the failure count and time variables considered in standard software reliability analyses. We consider a family of Poisson process models for which failure rates may depend on time as well as on the test effort variables. We analyze failure rates computed from this test data using least squares parameter estimation and model selection via the predicted residual sum of squares (PRESS)