1. A method for analyzing the performance of software development process activities, the method implemented on a computer system having a processor unit and comprising: selecting a process activity to be analyzed; determining a metric describing the performance of the selected process activity; collecting a number of metric data on the base of the selected process activities performed; analyzing the collected metric data and assessing the performance of the software development process activity by: (a) applying statistical process control (SPC) techniques, wherein a variation of the performance is affected by different types of variation comprising intrinsic process variation and Poisson effects, wherein a first SPC technique is applied with an assumption that the type of variation is only affected by Poisson effects to produce control charts for attributes data, and wherein a second SPC technique is applied with an assumption that the type of variation is only affected by intrinsic process variation to produce control charts for variable data; (b) integrating aspects of the control charts produced by the first and second SPC techniques into a combined SPC technique to address a mixture of the different types of variation by transformation of the collected metric data, wherein the collected metric data are each transformed into transformed metric data, adopted from control charts produced by the first SPC technique, comprising a distance from a centerline defined by a mean value of the metric data, wherein the metric data are normalized in units of an expected variation due to Poisson effects, wherein empirical natural process limits derived from a moving average of the transformed metric data are used to determine upper and lower control limits, adopted from control charts produced by the second SPC technique and wherein the transformed metric data in relation to the upper and lower control limits are used to assess the performance of the process.