Elements for Response Time Statistics in ERP Transaction Systems

The aim of this work is provide some insight into the response time statistics of enterprise resource planning systems. We propose a simple mean-field model for the response-time distribution in such systems. This model yields a log-normal distribution of response times. We present data from performance measurements to support the result. The data show that the response-time distribution of a given transaction in a given system is generically a log-normal distribution or, in some situations, a sum of two or more log-normal distributions. Deviations of the log-normal form can often be traced back to performance problems in the system. Consequences for the interpretation of response time data and for service level agreements are discussed.