All businesses have access to an extensive pool of knowledge, whether this is their understanding of customers' needs and the business environment or the skills and experience of employees. This has led to the use of different methodologies and strategies that are based on the type of evaluation required in the work. Accordingly, these research aims tie together the concept of knowledge management (KM), decision support system (DSS) and efficiency as a way of creation of continuable competitive advantage for the firms. A conceptual model is extracted from the literature review, developed and supported by knowledge experiences of senior workers. An initial study with consolidating firms that are effective in the industrial sector of the world was a lead to validating the study model and smoothing the progress of achieving investigation of the adopted relationships by the study. Collecting data was completed via interviews with managers and knowledge workers of the firms in addition to use of the survey questionnaire which was distributed to random samples from these firms. The research characterized a strong correlation between KM, DSS, and its types. Additionally, it characterized high correlation between DSS and efficiency. Therefore, the knowledge obtained in the current study could be updated for subsequent future steps in more development to the relationships among the same variables or other variables with KM.