You will prepare and submit a term paper on Information Systems Theory. Your paper should be a minimum of 5000 words in length. This system has become the focused area of latest research (Bose and Lou, 2011). The understanding of societal, organizational, and human interaction with technology is good defined through the information system theory (IST) (Rose & Scheepersm, 2001). The basic understanding about information system is described in figure below. Social Theory Information system Information system practices Fig.1 Theme of Information System Theory This report surveyed the main ideas about information system theory (IST). Theory of critical success factor and international information system are elaborated in the second and third sections of this report. The second and third section of the report is also representing the general strengths and weaknesses of Theory of critical success factor and international information system theory (IIS) theory. The Forth section will discuss the ways in which these approaches could be used and evaluated. The Fifth section is about the summary and conclusion. 2. Theory of Critical Success Factor 2.1 Main Idea The core success factors according to Wong and Tein about the information system are efficient, effective with a high reliability. For the achievement of success factors key development practices are followed. From available literature list of critical success factors are identified by Wong and Tein, some of them are: the improved information system is required to maintain the change management culture, system integration, software development training and testing, performance monitoring and evaluation, information system management structure. From the study some factors are identified that become the reasons of failure. Some of the factors like risk management and change management are not properly focused. Mismanagement of information system, delay in shipments due to lack of coordination or no proper use of information system. All mentioned factors are critical and need to address seriously, which can bring the organization in a better position. These factors could be converted into critical success factors for organization. The concept of critical theory is about the ethical and moral queries. The work in this area enhances and improves the human condition (Lee and Baskerville, 2003). The contribution of Rockart (1982) in the area of information system theory (IST) is vital for the theory of critical success factors. The information system is all about computer related things, environment and applications. The Computer hardware, software, application area, and communication come under the theory of information system theory (IST). The changes in the field of information system are vital, as information technology is growing day by day and same is adopted in the information system. The progress in the information system is in the form of centralized processing of data and distributed processing of data. In centralized data processing method, all systems are located at same geographical location, while in the case of distributed data processing all systems are dispersed in the different geographical locations. The key areas of activity for information system theory require some critical success factors. These critical success factors may vary from company to company. The nature of organization also provides success factors for it.