This study attempts to identify the prevailing Quality Management Systems (QMS) in IS industries and proposes means and ways by which it could be analysed, characterised, evaluated and improved to ensure the quality expected in software development activities. The study began with a proposition that the quality can be defined in several ways and the concept is dynamic because of very frequent changes in the factors that determined quality. Therefore, it was argued that the quality must be defined in terms of attributes that were satisfying the expectations of the customers. Though, the concept of quality was difficult to define precisely but there are guidelines to help develop quantitative measure of a quality. This was attempted in this study by preparing two hypothetical models one for the customers and another for the IS units and putting them to empirical test. The result showed that this approach yielded a reliable measure of quality. The IS units used the attributes identified by the customers for the quality of the products as the goal to be achieved with the help of QMS either singly or in combination. The result showed that the use of QMS was definitely advantageous over non-use of it. When combinations were used they provided further improvement in the quality as compared to their use individually, especially when TQM and SSM were part of these combinations. Thus, ISO, CMM and CMMI are seen to be in quality management through the attention to structural and process variables. TQM and SSM directly targeted the organizational goals to be realised to the highest level possible. Therefore, the combinations of TQM and SSM with other QMSs would take care of both structural and operational variables to enhance quality of products of Information System Development Units. © Research India Publications.