Management Movie Management System Customers Databases Vendors Check out movie Check in movie Add new customer Modify or delete a customer Add a new movie Modify or delete a movie Bill for unreturned movie Customers Databases Vendors

Documenting the New (or existing) Business Process: The products of the analysis phase: Data Flow Diagrams (DFDs) and Entity Relationship Diagrams (ERDs)

Signed Bill of Lading Notification Department of receipt Receive Goods Vendor Lading Signed Bill of Lading R. of G. Receipt of Goods File

Budget/Acct Information Vendor Expenditure Open P.O. File Invoice Department Budget/Acct Information Vendor Expenditure Open P.O. P.O. File Invoice Receipt of Check Make R. of G. Goods File Payment

Request Budget Availability Issue Purchase Department Budget/Acct Order Bud Commit Information Available Notification of receipt Vendors Expenditure P.O. Vendor Bill of Lading Receive Information Vendor Goods P.O. Signed BoL Open P.O. R. of G. P.O. File Invoice Receipt of R. of G. Check Make Goods File Payment

Department Vendor DFD Components: External Entities

Data Store Represented by a rectangle open at one end. Used when it is functionally necessary to store output from one process before sending it on to the next process. The data stores are the entities from the ERD!

DFDs do not show the flow of physical items, only of information DFDs do not show the flow of physical items, only of information. (Payment amounts etc. can be considered information.)

Request Budget Availability Issue Purchase Department Budget/Acct Order Bud Commit Information Available Notification of receipt Vendors Expenditure P.O. Vendor Bill of Lading Receive Information Vendor Goods P.O. Signed BoL Open P.O. R. of G. P.O. File Invoice Receipt of R. of G. Check Make Goods File Payment

Uses of Data Flow Diagrams As a Requirements Analysis Documentation Tool: Help analysts work out requirements with business management and users Help analysts communicate understandings with business management and users Help business management and users communicate As a basis for design: database design application software (process) design