1. Logical Models zDescribe what a system is or does. zAre independent of technical implementation. zDepict business requirements. zAre good for communicating with end users. zExamples: Data, process and object models.

2. Data Modeling zA technique for organizing and documenting a system’s data. zSometimes called database modeling or information modeling. zThe basic tool for data modeling is called an entity-relationship diagram (ERD).

3. Entity Relationship Diagrams (ERDs) zThree basic elements: yEntity types - the kinds of things the information system collects information about. y Relationship - the way an entity type is associated with another. yAttributes - specific information about an entity type.

4. ERDs z Professor Course Section Student Section Office Is registered in Has Teaches Types of relationships in entity-relationship Source: Alter S. (1999), Information Systems: A Management Perspective, Third Edition One-to-one relationship One-to-many relationship Optional one-to-many relationship Many-to-many relationship

5. Entity Relationship Diagram z Belongs to Department Student Section Professor Course Office Offers Has Teaches Is registered in Has Entity - Relationship Diagram for part of a university registration system Source: Alter S. (1999), Information Systems: A Management Perspective, Third Edition

6. Process Modeling zA technique for organizing and documenting ythe structure and flow of data through a system’s processes and/or ythe logic, policies, and procedures to be implemented by a system’s processes. (Whitten and Bentley 1998) zTools: data flow diagrams (DFD) and IDEF0

7. Data Flow Diagrams (DFDs) zFour basic symbols: yProcess - transforms inputs into outputs. yExternal entity - any person or organization that provides data to a process in the system or receives data from a process. Process External Entity

8. Data Flow Diagrams (DFDs) zData store - a location where data is stored. zData flow - represents movement of data between processes, data stores and external entities. Data Store Data Flow

9. Creating DFDs zStarting point is a context diagram, which verifies the scope of the system by showing the sources and destinations of data used and generated by the system. zSystem represented as a single process is at the center of the context diagram. zSurrounding that process are external entities and external data stores.

10. Creating DFDs (contd.) zThe business process in the context diagram is broken into its constituent processes to describe exactly how work is done. zThese constituent processes along with the data stores, external entities and data flows constitute the top level data flow diagram.

11. Creating DFDs (contd.) zConstituent processes can be broken into sub-processes. zDFDs make it possible to look at business processes at any level of detail. zIn addition to the context diagram, one or more DFDs are developed based on the level of detail required.

12. Purchasing system - Context diagram Invoice Material Planning Department Receiving Department PURCHASING SYSTEM Supplier Material requirement Confirmation of receipt Order Payment Context diagram for the Ford purchasing system Source: Alter S. (1999), Information Systems: A Management Perspective, Third Edition

13. Purchasing System - Data Flow Diagram z Material requirement Purchase order Receipt details Purchase order details Material Planning Department Receiving Department Supplier Purchase Orders Receipt Confirmations Order material Decide what to pay Pay the supplier PCH 1 PCH 2 PCH 3 Purchase order Invoice Payment Receipt confirmation Data flow diagram showing the main processes in Ford’s original purchasing system Source: Alter S. (1999), Information Systems: A Management Perspective, Third Edition Payment authorization

14. Integration Definition for Function (IDEF) z Background y Integrated Computer Aided Manufacturing (ICAM) program in US Air Force developed the IDEF series of techniques to improve manufacturing productivity. y IDEF0 - Function model, IDEF1 - Information model, IDEF2 - Dynamic model. z IDEF techniques widely used in government/industrial sectors.

15. IDEF0 Concepts zTechnique for performing and managing needs analysis, benefits analysis, requirements definition, functional analysis, and systems design. zReflects how system functions interrelate and operate.

16. IDEF0 Semantics zBox - Function (Ex. Perform Inspection) zLeft arrow - Inputs (Ex. Design data) zTop arrow - Controls (Ex. Design requirements) zBottom arrow - Mechanisms (Ex. Design Engineer) zRight arrow - Output (Ex. Detailed design)

17. IDEF0 Semantics (contd.) Input Mechanism Control Output Design data Engineer Requirements Detailed design FUNCTION DESIGN

18. IDEF0 Diagrams zIDEF0 models composed of: graphic diagrams, text, and glossary. zBoxes representing a function can be broken down or decomposed into more detailed diagrams. zTop level diagram in the model provides the most general description, with details provided in the lower levels.

19. Purchasing System - Context diagram Material requirements Confirmation of receipt Invoice PURCHASING SYSTEM Purchase Order Payment Policies and procedures Resources

20. Purchasing System - IDEF Diagram ORDER MATERIAL Material requirements Purchase order DETERMINE PAYMENT Receipt details Invoice PAY THE SUPPLIER Payment authorization Payment

21. Data Warehouses zUsed for building the data management infrastructure for DSSs and EISs. zA database (or collection of databases) that is optimized for decision support. zPopulated through the extraction and integration of data from both operational and external data sources.

22. Warehouse Architecture zThree types of components ythe platform and software (including the repository) that house the data warehouse, ythe data acquisition software or back end, which extracts data, consolidates and summarizes the data, and loads the data into the data warehouse, and ythe client or front end software, which allows users to access and analyze data.

23. Role of the Repository zTechnical role - to support the building and maintenance of the data warehouse. ydocument data sources and targets ydata transformation and cleanup rules yinterface to CASE tools ydocument warehouse data model zBusiness-related role - to support end users in accessing and analyzing data.

24. Data Marts zData stores specific to user-communities. zExamples are yEIS server for executives yDSS servers for departments (marketing, finance, and manufacturing) zData is structured in the form of a multi- dimensional database.

25. Multidimensional Analysis zAn analytical technique that allows users to view data in a dimensional cube format. zUsers can perform operations such as drill- down, roll-up, slice and dice, and data pivoting. zAnother term for multidimensional analysis is on-line analytical processing (OLAP).

26. Multidimensional Database zRelational structure - data is stored in a tabular form and is not preprocessed. Slow performance is an issue. zStar structure - two types of tables are used, fact and dimension. A “virtual” cube representation. zMultidimensional database - preprocessed data stored in the form of arrays.

27. MOLAP and ROLAP zMOLAP is OLAP with a multidimensional database. zROLAP or relational OLAP allows access to the data without building a specific multidimensional database. zMOLAP is suited for analysis on data marts in a multi-user environment.