Article explains the difference between Online Analytical Processing systems, Business Intelligence systems and Decision Support Systems.

There is often a debate in describing whether DSS is different from BI. Answer is Yes, the terminologies differ. While DSS is usually referred to one methodology which helps for organizational business decisions, BI is an umbrella term to refer to an array of techniques/methodologies that address organizational business questions.

Online Analytical Processing (OLAP)

Online Analytical Processing (OLAP) is the approach involved in providing analysis to multidimensional data. There are various forms of OLAP namely

• Multidimensional OLAP (MOLAP) – This uses a cube structure to store the business attributes and measures. Conceptually it can be considered as multi-dimensional graph having various axes. Each axis represents a category of business called a dimension (eg location, product, time, employee etc). The data points are the business transactional values called measures. The coordinate of each data point related it to the business dimension. The cubes are generally stored in proprietary format.
• Relational OLAP (ROLAP) – This uses database to store the business categories as dimension tales (containing textual business attributes and codes) and the fact tables to store the business transactional values (numeric measures). The fact tables are connected to the dimension tables through the Foreign-Key relationships.
• Hybrid OLAP (HOLAP) – This uses a cube structure to store some business attributes and database tables to hold the other attributes.

Business Intelligence (BI)

Business Intelligence (BI) is a generic term used for the processes, methodologies and technologies used for collecting, analyzing and presenting business information.

The objective of BI is to support users make better business decisions. The objective of DWH and BI go hand-in-hand, that of enabling users make better business decisions.

Data marts/warehouses provide easily accessible historical data to the BI tools to provide end users with forecasting/predictive analytical capabilities and historical business patters and trends.

BI Tools are generally accompanied with reporting features like Slice-and-dice, Pivot-table-analysis, Visualization, and statistical functions that make the decision making process even more sophisticated and advanced.

Decision Support Systems (DSS)

A Decision Support System (DSS) is used for management based decision making reporting. It is basically an automated system to gather business data and help make management business decisions.