The modeling of the software test process using a state variable approach and the use of control theory concepts to regulate the process and calibrate the model has proven to be a valuable alternative for software process control. In this paper a description of the current status of the technique along with recent model improvements are presented. The architecture of a web-based tool to hide the complexity of the model and algorithms and increase the applicability of the technique is also presented. Finally, the directions of future research toward improvement in the accuracy of the model and in the calibration algorithm are described.