Software development project employs some quality control (QC) process to detect and remove defects. The final quality of the delivered software depends on the effort spent on all the QC stages. Given a quality goal, different combinations of efforts for the different QC stages may lead to the same goal. In this paper, we address the problem of allocating resources to the different QC stages, such that the optimal quality is obtained. We propose a model for the cost of QC process and then view the resource allocation among different QC stages as an optimization problem. We solve this optimization problem using non-linear optimization technique of sequential quadratic programming. We also give examples to show how a sub-optimal resource allocation may either increase the resource requirement significantly or lower the quality of the final software.