Personal software process quality helps determine the success of software projects and organizations. Although encouraging, previous studies treated the Personal Software Process approach as a black-box tool for personal process improvement. We dig deeper into the factors affecting personal processes. It is concluded that A/FR (appraisal to failure ratio) and Yield (percentage of defects removed before first compile) are two critical factors affecting personal software processes. Because the findings are limited to one experiment involving subjects in a university setting, developers in an industrial environment should use them with caution. We expect readers to view this article as hopeful; we call for more of such studies in academia and industry. With additional studies, we can collectively build stronger theories underlying personal software processes.