Systems Analysis and Design Tutorial
A decision support system is a type of application system that is designed specifically to read data and present it to decision makers in a format that is suitable for decision making.
Decision support systems often use information from multiple systems of record. The data from these source systems is cleansed, integrate and made available to system users in report formats, spreadsheet formats and/or via online analytic tools that permit “drill-down” capabilities.
Data warehousing tools and techniques are often used to consolidate data from multiple, disparate data sources. They alleviate data fragmentation, correctness and completeness problems that result from poorly integrated operational systems.
Although decision support application systems support strategic, tactical and operational decision making, they don't provide online functionality for data to be added, changed or deleted. Instead, data is copied from systems of record into the decision support database.