The aim of this empirical study was to elucidate organizational and customer related challenges that affect the software testing process in software developing companies and how these challenges affect software quality construction. Using the grounded theory research method, we studied eleven software companies operating in different domains such as banking, space satellites, health care and energy. Seven main findings are presented: First, the low involvement of testers in the planning phase of the software development life cycle (SDLC) led to underestimation of the scope of testing and resources required. Second, there was poor buy-in for testing from project managers, which led to insufficient involvement of testers in some SDLC activities. Third, the risk-taking behaviour of project managers led them to skip important tests. Fourth, vertical organizational structures and modes of operation within the companies limited the mandate and visibility of testing and quality assurance units in development projects. Fifth, oversights in budgeting and contracts between customers and the software developing companies limited the extent of testing. Sixth, resources management, which was related to poor use of available systems, created a communication gap between teams and conflict in requirements interpretation; and seventh, customers' willingness to co-operate in after-sales testing limited the extent and efficiency of such testing and thus affected software quality.