The quality of software products is now considered to be an essential element in business success. The software industry has for many years been putting considerable effort into trying to improve the quality of their products and the main focus up to now has been on software process improvement as an indirect approach to achieving that quality. Therefore, there are numerous maturity models in the software engineering literature for assessing and evaluating a set of software processes. By contrast, there is no corresponding maturity model for assessing the quality of a software product. Our main goal is to make available to industry a maturity model for assessing the quality of the software product. In particular, such a product quality model can be used to: certify a quality maturity level for a new software product, benchmark existing software products to assist in making a selection based on their quality maturity level, assess the quality of the software product during the development life-cycle, and assess the maturity of the internal quality of a software product to be reused in other software products.