Course Hero has millions of student submitted documents similar to the one below including study guides, practice problems, reference materials,

Course Hero has millions of student submitted documents similar to the one below including study guides, practice problems, reference materials, practice exams, textbook help and tutor support. 8 Systems Chapter Analysis and Design Instructor’s Manual 8-1 Chapter 8 Analyzing Systems Using Data Dictionaries 1 Key Points and Objectives 1. A data dictionary is a main method for analyzing the data flows and data stores of data-oriented systems. 2. The data dictionary is a reference work of data about data (metadata) compiled by systems analysts to guide them through analysis and design. It collects, coordinates, and confirms what a specific data term means to different people in the organization. 3. The data dictionary may be used for the following reasons: A. B. C D. E. F. G. 4. Providing documentation Eliminating redundancy Validating the data flow diagram for completeness and accuracy Providing a starting point for developing screens and reports Determine the contents of data that is stored To develop the logic for data flow diagram processes Create XML (extensible markup language) A data repository is a large collection of project information. It includes: A. B. C. D. E. F. Information about system data, including data flows, data stores, record structures, elements, entities, and messages Procedural logic and use cases Screen and report design Relationships between entries Project requirements and deliverables Project management information 5. Each data flow should be defined with descriptive information and its composite structure (elements). 6. Data structures are a group of smaller structures and elements. 7. An algebraic notation is used to represent the data structure. The symbols used are: A. B. C. D. E. Equal sign, meaning consists of Plus sign, meaning “and” Braces {} meaning repetitive elements, a repeating element or group of elements Brackets [] for an either/or situation Parentheses () for an optional element Chapter 8 Analyzing Systems Using Data Dictionaries 8-2 8. Data structures may be either logical or physical. 9. Logical data structures reflect the mental model of how the users view the system. 10. Physical data structures include elements and information necessary to design and implement the computer system. Additional elements on these structures include: A. B. C. D. E. F. Key fields used to locate records. Codes to indicate record status. Codes to identify records when multiple record types exist on a single file. A count of how many entries are actually in a repeating group. Limits on the number of items in a repeating group. A password used by a customer accessing a secure Web site. 11. Data elements should be defined with descriptive information, length and type of data information, validation criteria and default values. 12. Data stores must be defined. They contain a minimal of all base elements as well as many derived elements. 13. Data stores definitions contain descriptive information as well as physical characteristics. The name of the data structure found within the data store should be included. 14. Data dictionary entries vary according to the level of the corresponding data flow diagram. 15. Data dictionaries are created in a top-down manner. 16. A starting point in creating data dictionary entries is to analyze user input and output requirements. 17. Data stores may be determined by analyzing data flows. Each data store should consist of elements on the data flows that are logically related, meaning they describe the same entity. 18. To have maximum power, the data dictionary should be tied into other programs in the system so that when an item is updated or deleted from the data dictionary it is automatically updated or deleted from the database. Otherwise, the data dictionary becomes only a type of historic document of the system. 19. Data dictionaries may be used to: A. B. C. D. Create reports, screens and forms. Generate computer program source code. Analyze the system design for completion and to detect design flaws. Create XML document structures. 20. Data dictionaries may be used to create extensible markup language (XML). 21. XML is used to share data between two different computer systems. 22. An XML document may be used to define, filter, sort and transform data. Chapter 8 23. 8-3 A document type definition (DTD) is one way to define what is allowed in an XML document, and can include: A. B. E. F. 24. Systems Analysis and Design Instructor’s Manual The order of the elements. If an XML element is repeatable, and whether there must be at least one of the element. An optional element. Definition of attributes. An XML schema is another more precise way to define the content of an XML document. Consulting Opportunity 8.1 (p. 281) Want to Make It Big in the Theatre? Improve Your Diction(ary)! Listed below are some suggested data flow, stores, etc. DATA FLOW DESCRIPTION Name: Order details Description: Details of the customer order, including customer information and costume types and quantities. Source: Data store D3, Customer Order Type of data flow File Screen Report Form Destination: Process 3, Prepare Shipping Invoices Internal Data Structure Traveling With The Flow: Order Details Volume/Time 1200/day Comments DATA FLOW DESCRIPTION Name: Shipping invoice Description: Contains details and summary totals for the customer order. Source: Process 3, Prepare shipping invoices Type of data flow File Screen Report Form Destination: External entity, Customers Internal Data Structure Traveling With The Flow: Shipping Invoice Comments Volume/Time 1200/day Chapter 8 Analyzing Systems Using Data Dictionaries 1 DATA STORE DESCRIPTION FORM ID: D1 Name: Costumes In Inventory Alias: Description: Contains information on all costumes in inventory. File Type File Format Data Store Characteristics Manual Indexed Direct Computer Database Record Size (Characters): 200 Block Size: 4000 Average Number Of Records: 2000 Maximum Number Of Records: 2000 Percent Growth per year: 5 Data Set Name: COSTUME.MST Copy Member: COSTMSTR Data Structure: Costume Master Record Primary key: Inventory Number Secondary keys: Costume Number Comments 1 DATA STORE DESCRIPTION FORM ID: D2 Name: Customer Information Description: Contains one record for each customer. Data Store Characteristics File Type File Format Computer Database Manual Indexed Record Size (Characters): 200 Block Size: 4000 Direct Average Number Of Records: 2000 Maximum Number Of

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