1. Decision Support System ISYS 363

2. Decision supports Systems Components Data management function –Data warehouse Model management function –Analytical models: Statistical model, management science model User interface –Data visualization

3. Using Decision Support Systems What-IF Analysis:Observing how changes to selected variables affect other variables. Sensitivity Analysis: Observing how repeated changes to a single variable affect other variables. Goal-Seeking Analysis:Set a target value for a variable, and then repeatedly changes other variables until the target is achieved. –Data/What If analysis/Goal seek –Example: Benefit.Xls Optimization Analysis Simulation

4. New Developments in Decision Support Systems Data visualization: Representing data in graphical/multimedia formats for analysis. –Web-based “dashboards” http://www.corda.com/centerview-executive- dashboard-product-tour.php,http://www.corda.com/centerview-executive- dashboard-product-tour.php –Product tour –Retail sales Data warehousing Geological Information System, GIS What-if scenarios

5. Data Warehouse A subject-oriented, integrated, time-variant, non-updatable collection of data used in support of management decision-making processes –Subject-oriented: e.g. customers, employees, locations, products, time periods, etc. Dimensions for data analysis –Integrated: Consistent naming conventions, formats, encoding structures; from multiple data sources –Time-variant: Can study trends and changes –Nonupdatable: Read-only, periodically refreshed

6. Data Warehouse Design - Star Schema - Fact table –contain detailed business data Ex. Line items of orders to compute total sales by product, by salesperson. Dimension tables –contain descriptions about the subjects of the business such as customers, employees, locations, products, time periods, etc.

7. Example: Order Processing System Customer Order Product Has 1 M M M CID Cname City OIDODate PID Pname Price Rating SalesPerson Qty

8. Star Schema FactTable LocationCode PeriodCode Rating PID Qty Amount Location Dimension LocationCode State City CustomerRating Dimension Rating Description Product Dimension PID Pname Category Period Dimension PeriodCode Year Quarter Can group by State, City

9. Snowflake Schema FactTable LocationCode PeriodCode Rating PID Qty Amount Location Dimension LocationCode State City CustomerRating Dimension Rating Description Product Dimension PID Pname CategoryID Product Category CategoryID Description Period Dimension PeriodCode Year Quarter Can group by State, City

10. The ETL Process E T L One, company- wide warehouse Periodic extraction  data is not completely current in warehouse

11. The ETL Process Capture/Extract Transform –Scrub(data cleansing),derive –Example: City -> LocationCode, State, City OrderDate -> PeriodCode, Year, Quarter Load and Index ETL = Extract, transform, and load

12. From SalesDB to MyDataWarehouse Extract data from SalesDB: –Create query to get the data –Download to MyDataWareHouse Transform: –Transform City to Location –Transform Odate to Period Query FactPC Load data to FactTable

13. Star schema example Fact table provides statistics for sales broken down by product, period and store dimensions Dimension tables contain descriptions about the subjects of the business

14. Star schema with sample data

15. Geological Information System GIS GIS is a computer-based tool for mapping and analyzing things that exist and events that happen on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps.

16. Data of GIS Geodatabase: –A geodatabase is a database that is in some way referenced to locations on the earth. Longitude, latitude Attribute data: –Attribute data generally defined as additional information, which can then be tied to spatial data. Example: Google Earth

17. Scenario A scenario is an assumption about input variables. Excel’s Scenarios is a what-if-analysis tool. A scenario is a set of values that Microsoft Excel saves and can substitute automatically in your worksheet. You can use scenarios to forecast the outcome of a worksheet model. You can create and save different groups of values on a worksheet and then switch to any of these new scenarios to view different results. Data/What If analysis/Scenario

18. Creating a Scenario –Add scenario Changing cells Resulting cells Demo: benefit.xls