Mapping bugs with the source code, without superimposing any overhead on the development team, represents a paramount opportunity to keep a software project under control. Lagrein is a Eclipse RCP based software system that tries to address this problem by supporting managers and developers in the quality improvement of the software system under development. It supports the visualization of multiple metrics (using GEF) selected using System Query Language (SyQL). The visualization enables the user to see the “most interesting” parts of the system. With this tool is possible to couple a reported bug with the methods that produce it. With a certain level of approximation, Lagrein makes possible to estimate the fault-proneness of each method using an effort/metrics estimation model. The software process mining task can be tackled using SyQL, this language helps the project supervisors to evaluate metrics by linguistic variable conditions. This feature makes easier evaluate the effort and other software metrics.