In the world today, information technology and information systems (IT/IS) are no longer as work tools or as production resources, but they are considered as new environment and work space. This new environment or work space has provided an area for great developments including a change in the method of organizing and presenting new organizational forms such as knowledge worker’s organization, network organization, virtual organization, and so on.
Regarding the effects of IT/IS on organizational structures and its dimensions, many investigations have been carried out during the last 3 decades but the findings from these studies are contradictory. On the other hand, considering the changes in the vast variety of IT/IS and changes in the applications and capabilities of IT/IS, the generalization of the last research findings has decreased in this regard. Hence, while determining the last research results, the present article has attempted to design and determine a comprehensive model for integration of the literature, regarding this issue in the theoretical field according to the new cases of IT/IS such as different information systems, internet, intranet, extranet, video conference, e-mail and so on, and to identify two adjusting variables of effects on organization structure by IT/IS. For this purpose, in order to acquire more understanding of IT/IS effects on organization structure as well as to recognize the effect of two adjusting variables on the top management leadership style and its attitude towards IT/IS on organizational structure in spare parts building

industries of Iran’s Automobile, three questionnaires have been used. These questionnaires were distributed as an existing status evaluation questionnaire of information technology and information systems (IT/IS) in companies, a questionnaire relating to organization structure of companies and a questionnaire for determination of top management leadership style in an organization among the successful companies of Iran’s automobile part-building industries. In each company, three people from the managerial levels (the managing director, administrative and human resources manager and IT manager) answered the questions. Data collected from the companies were analyzed by using the SPSS /11.5 software, and hypotheses based on research model were tested and, at the end, a comprehensive organizational design commensurate with information technology and information system (IT/IS) was presented.