A Decision Support System is the computer based information system previously mentioned. It is the technology that enables the high speed of decision making and action. It is the mainframe which houses all the previous data the business collects about the market and current relevant business information, such as currency values, share values, and trading trends, but also allows inter-communication between companies and internally in those companies. Such technology allows the rapid construction of data models and the observation of trends faster than people might usually predict or pick up on.
The Decision Support System is useful for executive decision making because it facilitates them; it gives them the knowledge they need to make the judgments that count. An informed judgment based on factual evidence is far more likely to be beneficial than one based on presumption.
The executive support system must be flexible and easy to use because these are business people, not I.T. Specialists. If the system is too complicated to be used quickly and easily then it won't generate the increased productivity it is capable of.