Information Systems for Managers
About this eBook
customers through auction. There are e-businesses who are content provider and manager. The companies where core competence is not IT, hire an IT company to create web sites and databases for them. Some companies provide portals to other organizations. A portal is a web site that provides an initial entry point to the web site of the company or other services e.g. Yahoo is a portal. The e-commerce can also be classified based on the parties involved in the business. A business-to-consumer e-business involves an electronic retail home and customers. Such a business is also called B2C business, www.amazon.com is an example of B2C business. Business-to-business B2B involves transaction among businesses. The main advantage is that a business house can buy raw material and supplies from another business party without going through the retailer. www.Milpro.com is an ebusiness, which sells machine tools to other businesses. In a consumer-to-consumer business C2C , the e-business is a facilitator only. People are able to sell to other people using a C2C facility.
1.7 COMPUTER AIDED DECISION MAKING A decision system supports and assists all aspects of problem specific decisionmaking. A decision support system DSS , also called Computer Aided Decision System CADS , is used when the problem is complex and the information needed to make the best decision is difficult to obtain and use. In an organization, a manager has certain goals, which he tries to achieve through the use of resources. The resources such as people, money, material, and time is always limited. One of the roles that a manager plays among many others is of decisionmaking. The manager would like to examine various alternatives, which may not be possible in a manual system due to time constraint or due to sheer volume of data. Sometimes, a statistical analysis of fluctuating data is required which may be done only with the help of a decision support system. The data may be distributed over various branches of the organization and without the help of Information Technology it may not be possible to examine the data. An information system that helps a manager in making a decision is called a computer-aided decision support system CADS or simply decision support system DSS . A DSS is designed with the help of decision makers. A DSS aids in decisionmaking process and does not make any decision. A DSS may be used for doing a thorough risk analysis of a project. Such a DSS performs what - if analysis. A DSS consists of a model of the real world, collection of facts- database, and a user interface. 8
An analyst talks to the manager and tries to establish his requirement. Analyst may need to interact with users many times before the requirements are completely understood. The analyst may also study the existing system if any. The analyst must have domain knowledge. The reality is examined, the problem is identified, and it is defined. The problem may be too complex to be analyzed. In such a situation, a simplified version of the problem is defined. The simplified problem is used to create a model of the actual problem. There are many ways of creating a model for a problem. The model may be a scale model, i.e. model of a building or a bridge. It may be a mathematical model such as equations describing the trajectory of a missile. The model may be an analog model such as a blue print for a building or a map to show a particular region. There are many other types of models, which are not discussed here. A model has a set of uncontrollable variables that are not under the control of the manager. There is a set of decision variables, which are under the control of the manager, and these variables describe alternative course of action. As the values assigned to decision variables are changed, the results also change. The result variables are dependent on decision variables.