The paper deals with the problem of monitoring software development and maintenance processes. In particular, we concentrate on data reported in software bug repositories. These data characterize the progress and effectiveness of the above mentioned processes. To analyze these data we have developed a special program which extracts information from typical bug repositories (e.g. Bugzilla) and generates various useful statistics. The analysis methodology is based on problem handling graphs (PHGs) and various metrics. The usefulness of this approach has been illustrated for some real open source and commercial projects. We present the measurement methodology and interpretation of the obtained results, which confirmed their practical significance.