Data warehouses can become enormous with hundreds of gigabytes of transactions. As a result, subsets, known as "data marts," are often created for just one department or product line. Data Warehouse combines databases across an entire enterprise. However, Data Marts are usually smaller and focus on a particular subject or department or product line.
Following are the common techniques through which a data warehouse can be used.
Decision support software that allows the user to quickly analyze information that has been summarized into multidimensional views and hierarchies. The term online refers to the interactive querying facility provided to the user to minimize response time. It enables users to drill down into large volume of data in order to provide desired information, such as isolating the products that are more volatile from sales data. OLAP summarizes transactions into multidimensional user defined views.
CBIS can be divided into subsystems based on how the users are grouped in the organization. This grouping of users is in terms of related tasks that are performed. These conceptual systems are mirror images of physical systems that are present. These systems are collectively called Organizational Information systems (OIS).
The term OIS views organization as a combination of process oriented groups whose information needs are related but independent. All functional systems should work together for problem solving since each system specialises in specific domain of information.
Departments are structured based on the set of related responsibilities. The set of responsibilities being discharged set the tone and structure of that department. The complexity and diversity of these responsibilities also affect how departments are set in an organization.
Existence of Functional departments in every organization vary with the nature of industry and the nature of products/services being offered
Certain departments may not exist in an organization, for instance financial sector (banking, leasing companies) and travel agencies do not incorporate the concept of manufacturing as they belong to the services sector.
Let’s take a look at different departments in different industry segments in order to better understand the concept.
No information system can exist in an organization without being linked with other functional information systems. This linkage is important for the over all smooth functionality of the information system since it allows easy transformation and usage of information.