The process of choosing among competing alternatives is decision making. Decisions can be improved if information about the alternatives is gathered and made available to managers. One of the major roles of the accounting information system is to supply information that facilitates decision making. This pervasive managerial function is an important part of both planning and control. A manager cannot plan without making decisions. Managers must choose among competing objectives and methods carry out the chosen objectives. Only one of numerous mutually exclusive plans can be chosen. Similar comments can be made concerning the control function.