Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition C H A P T E R 7 DATA MODELING AND ANALYSIS Part 3

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Chapter SevenData Modeling and Analysis Discover entities and relationships. Construct an entity-relationship context diagram. Discover or invent keys for entities and construct a key-based diagram. Construct a fully attributed entity relationship diagram and describe all data structures and attributes to the repository or encyclopedia.

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Chapter Map

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition The Key-based Data Model

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition The Key-based Data Model With Generalization AUDIO TITLE Primary Key Product-Number [PK1] [FK] VIDEO TITLE Primary Key Product-Number [PK1] [FK] GAME TITLE Primary Key Product-Number [PK1] [FK] TITLE Primary Key Product-Number [PK1] [FK] MERCHANDISE Primary Key Product-Number [PK1] [FK] TRANSACTION Primary Key Transaction-Reference-Number [PK1] MEMBER ORDERED PRODUCT Primary Key Order-Number [PK1] [FK] Product-Number [PK2] [FK] PROMOTION TITLE Primary Key Promotion-Number [PK1] [FK] Product-Number [PK2] [FK] MEMBER ORDER Primary Key Order-Number [PK1] MEMBER Primary Key Member-Number [PK1] PRODUCT Primary Key Product-Number [PK1] AGREEMENT Primary Key Agreement-Number [PK1] PROMOTION Primary Key Promotion-Number [PK1] is featured as features sold as sells places binds is a has conducted responds to is a generates

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition The Fully-Attributed Data Model

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Exercise Let’s build an entity relationship diagram together. We need an information system with which we all have familiarity. Let’s do a bank account information system from the viewpoint of the customer. First we need a list of entities and relationships. This is the entity discovery step. The product is a context data model. –During an interview track “key words” –Think of forms and what entities they describe –Some CASE tools can reverse engineer entities –Entities can have multiple instances –Entities should be named with singular nouns –Relationships are verb phrases

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Fundamental Entities Entity NameBusiness Definition DepositAdding money to account WithdrawalRemoval of money from account. TransferSwitching money between accounts. Bank personnelIndividuals you interact with at the bank. CustomerPersonal information, address, ss#. Saving AccountA bank account that provides interest and does not permit checking. Checking AccountA bank account that provides checking but not interest. ATM ServiceAccess to accounts through ATM machines. On-line BankingAccounts available through internet Loan officerProvide service to acquire a loan (educational loan, mortgage, car loan).

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Context Data Model Loan Officer On-Line ATM Checking Savings Customer Bank Personnel Transfer Deposit Withdrawal withdraws transfers makes Transfers to Transfers from

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Context Data Model Geb’s Revision Check On-Line transaction ATM transaction Checking Account Savings Account Interest Payment Transfer Deposit Withdrawal withdraws deposits Transfers to Transfers from Bank Account Is a Bank Fee generates

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Key-based data model The next step is to assign keys to each of our entities. This is a key-based data model

Irwin/McGraw-Hill Copyright © 2000 The McGraw-Hill Companies. All Rights reserved Whitten Bentley DittmanSYSTEMS ANALYSIS AND DESIGN METHODS5th Edition Fully attributed data model Next we need to add the attributes to each entity in the diagram