Decision supports Systems Components

• Data management function– Data warehouse

• Model management function– Analytical models:

• Statistical model, management science model

• User interface– Data visualization

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-dashb

oard-product-tour.php,

– Product tour

– Retail sales

• Data warehousing

• What-if scenarios

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

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.

The ETL Process

E

T

LOne, company-wide warehouse

Periodic extraction data is not completely current in warehouse

The ETL Process

• Capture/Extract

• Transform–Scrub or data cleansing

• Load and Index

ETL = Extract, transform, and load

Example:Order Processing System

Customer Order

Product

Has

Has

1 M

M

M

CID Cname City OID ODate

PIDPname

Price

RatingSalesPerson

Qty

Star Schema

FactTableLocationCodePeriodCode

RatingPIDQty

Amount

LocationDimension

LocationCodeStateCity

CustomerRatingDimension

RatingDescription

ProductDimension

PIDPname

CategoryID

ProductCategory

CategoryIDDescription

PeriodDimensionPeriodCode

YearQuarter

Can group by State, City

From SalesDB to MyDataWarehouse

• Extract data from SalesDB:– Create query to get the data– Download to MyDataWareHouse

• File/Import/Save as Table

• Transform:– Transform City to Location– Transform Odate to Period

• Query FactPC

• Load data to FactTable

On-Line Analytical Processing (OLAP) Tools

• The use of a set of graphical tools that provides users with multidimensional views of their data and allows them to analyze the data using simple windowing techniques

• Relational OLAP (ROLAP)– Traditional relational representation

• Multidimensional OLAP (MOLAP)– Cube structure

• OLAP Operations– Cube slicing–come up with 2-D view of data– Drill-down–going from summary to more detailed

views– Roll-up – the opposite direction of drill-down– Reaggregation – rearrange the order of dimensions

Slicing a data cube

Example of drill-down

Summary report

Drill-down with color added

Starting with summary data, users can obtain details for particular cells

Geological Information SystemGIS

• 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.

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

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.

Creating a Scenario

• Tools/Scenarios– Add scenario

• Changing cells• Resulting cells

• Demo: benefit.xls

Chart

Charting Decision Rules

• An Internet Service Provider charges customers based on hours used:– First 10 hours $15– Each of the next 20 hours $2 per hour– Hours over 30 hours $1 per hour

Comparing Decision Rules

• Plan 2:– First 20 hours: $20– Hours over 20 $1.5

• Plan 3:– $35 unlimited access.

Charting Functions

• Demand function:– P = 150 – 6*Q^2

• Supply function:– P = 10* Q^2 + 2*Q

• Note:– Positive area– Value axis maximum/minimum value:

• Format Value Axis