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Chapter 1 Assuming the Role of the Systems Analyst Systems Analysis and Design Kendall Chapter 1 Assuming the Role of the Systems Analyst Systems Analysis and Design Kendall and Kendall Fifth Edition © Copyright Prentice Hall, 2002

Major Topics n n n Information systems Phases of analysis and design System maintenance Major Topics n n n Information systems Phases of analysis and design System maintenance CASE tools Alternate methodologies Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 2

Information n Information is an organizational resource which must be managed as carefully as Information n Information is an organizational resource which must be managed as carefully as other resources Costs are associated with information processing Information processing must be managed to take full advantage of its potential Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 3

Categories n Information systems fall into one of the following eight categories: n n Categories n Information systems fall into one of the following eight categories: n n n n Kendall & Kendall Transaction processing systems (TPS) Office automation systems (OAS) Knowledge work systems (KWS) Management information systems (MIS) Decision support systems (DSS) Expert systems (ES) Group decision support systems (GDSS) Executive support systems (EES) Copyright © 2002 by Prentice Hall, Inc. 4

New Technologies n New technologies are being integrated into traditional systems n n Kendall New Technologies n New technologies are being integrated into traditional systems n n Kendall & Kendall Ecommerce uses the Web to perform business activities Enterprise Resource Planning (ERP) has the goal of integrating many different information systems within the corporation Wireless and handheld devices, including mobile commerce (mcommerce) Open source software Copyright © 2002 by Prentice Hall, Inc. 5

Advantages of Using the Web n n Increasing awareness of the availability of the Advantages of Using the Web n n Increasing awareness of the availability of the service, product, industry, person, or group 24 -hour access for users Standard interface design Creating a global system Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 6

Nature of Analysis and Design n Systems analysis and design is a systematic approach Nature of Analysis and Design n Systems analysis and design is a systematic approach to identifying problems, opportunities, and objectives; analyzing the information flows in organizations; and designing computerized information systems to solve a problem Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 7

Systems Analyst n Systems analysts act as n n n Outside consultants to businesses Systems Analyst n Systems analysts act as n n n Outside consultants to businesses Supporting experts within a business As change agents Analysts are problem solvers, and require communication skills Analysts must be ethical with users and customers Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 8

Systems Development Life Cycle n n n The systems development life cycle is a Systems Development Life Cycle n n n The systems development life cycle is a systematic approach to solving business problems It is divided into seven phases Each phase has unique activities Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 9

Phase 1 n Identifying n n Problems Opportunities Objectives Personnel involved n n n Phase 1 n Identifying n n Problems Opportunities Objectives Personnel involved n n n Analyst User management Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 10

Phase 2 n Determining information requirements n n n Interview management, operations personnel Gather Phase 2 n Determining information requirements n n n Interview management, operations personnel Gather systems/operating documents Use questionnaires Observe the system and personnel involved Learn the who, what, where, when, and how, and the why for each of these Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 11

Phase 2 n Personnel involved n n Analyst User management User operations workers Systems Phase 2 n Personnel involved n n Analyst User management User operations workers Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 12

Phase 3 n Analyzing system needs n n n Create data flow diagrams Document Phase 3 n Analyzing system needs n n n Create data flow diagrams Document procedural logic for data flow diagram processes Complete the data dictionary Make semistructured decisions Prepare and present the system proposal Recommend the optimal solution to management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 13

Phase 3 n Personnel involved n n n Analyst User management Systems management Kendall Phase 3 n Personnel involved n n n Analyst User management Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 14

Phase 4 n Designing the recommended system n Design the user interface n n Phase 4 n Designing the recommended system n Design the user interface n n n Design output Design input Design system controls Design files and/or database Produce program specifications Produce decision trees or tables Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 15

Phase 4 n Personnel involved n n n Analyst System designer User management User Phase 4 n Personnel involved n n n Analyst System designer User management User operations workers Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 16

Phase 5 n Developing and documenting software n n Design computer programs using structure Phase 5 n Developing and documenting software n n Design computer programs using structure charts, Nassi-Schneiderman charts, and pseudocode Walkthrough program design Write computer programs Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 17

Phase 5 n Personnel involved n n Analyst System designer Programmers Systems management Kendall Phase 5 n Personnel involved n n Analyst System designer Programmers Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 18

Phase 6 n Testing and maintaining the system n n n Test and debug Phase 6 n Testing and maintaining the system n n n Test and debug computer programs Test the computer system Enhance system Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 19

Phase 6 n Personnel involved n n Analyst System designer Programmers Systems management Kendall Phase 6 n Personnel involved n n Analyst System designer Programmers Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 20

Phase 7 n Implementing and evaluating the system n n n Plan conversion Train Phase 7 n Implementing and evaluating the system n n n Plan conversion Train users Purchase and install new equipment Convert files Install system Review and evaluate system Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 21

Phase 7 n Personnel involved n n n Analyst System designer Programmers User management Phase 7 n Personnel involved n n n Analyst System designer Programmers User management User operations workers Systems management Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 22

Rapid Application Development n Rapid Application development (RAD) is an object-oriented approach to systems Rapid Application Development n Rapid Application development (RAD) is an object-oriented approach to systems development Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 23

System Maintenance n System maintenance is n n n Removing undetected errors, and Enhancing System Maintenance n System maintenance is n n n Removing undetected errors, and Enhancing existing software Time spent on maintenance typically ranges from 48 -60 percent of total time Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 24

System Enhancements n Systems are enhanced for the following reasons: n n n Adding System Enhancements n Systems are enhanced for the following reasons: n n n Adding additional features to the system Business and governmental requirements change over time Technology, hardware, and software rapidly changing Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 25

CASE Tools n n CASE tools are automated, microcomputerbased software packages for systems analysis CASE Tools n n CASE tools are automated, microcomputerbased software packages for systems analysis and design Four reasons for using CASE tools are: n n Kendall & Kendall To increase analyst productivity Facilitate communication among analysts and users Providing continuity between life cycle phases To assess the impact of maintenance Copyright © 2002 by Prentice Hall, Inc. 26

CASE Tool Categories n CASE tools may be divided into several categories n n CASE Tool Categories n CASE tools may be divided into several categories n n n Upper CASE (also called front-end CASE) tools, used to perform analysis and design Lower CASE (also called back-end CASE). These tools generate computer language source code from CASE design Integrated CASE, performing both upper and lower CASE functions Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 27

Upper CASE n Upper CASE tools n n Create and modify the system design Upper CASE n Upper CASE tools n n Create and modify the system design Store data in a project repository The repository is a collection of records, elements, diagrams, screens, reports, and other project information These CASE tools model organizational requirements and define system boundaries Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 28

Lower CASE n n Lower CASE tools generate computer source code from the CASE Lower CASE n n Lower CASE tools generate computer source code from the CASE design Source code may usually be generated in several languages Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 29

Advantages of Generating Code n n n Time to develop new systems decreases The Advantages of Generating Code n n n Time to develop new systems decreases The time to maintain generated code is less than to maintain traditional systems Computer programs may be generated in more than one language CASE design may be purchased from thirdparty vendors and tailored to organizational needs Generated code is free from program coding errors Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 30

Reverse Engineering n n Reverse engineering is generating the CASE design from computer program Reverse Engineering n n Reverse engineering is generating the CASE design from computer program code Source code is examined, analyzed, and converted into repository entities Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 31

Reverse Engineering Produces n Reverse engineering produces (depending on the tool set used) n Reverse Engineering Produces n Reverse engineering produces (depending on the tool set used) n n n Data structures and elements, describing the files, records, and field Screen designs, if the program is online Report layouts for batch programs A structure chart showing the hierarchy of the modules in the program Database design and relationships Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 32

Advantages of Reverse Engineering n It has the following advantages: Reduced system maintenance time Advantages of Reverse Engineering n It has the following advantages: Reduced system maintenance time n Program documentation is produced for loosely documented programs n Structured programs may be generated from unstructured, older programs n Future system maintenance is easier to implement n Unused portions of programs may be eliminated Kendall & Kendall n Copyright © 2002 by Prentice Hall, Inc. 33

Object-Oriented Analysis and Design n n Object-oriented (O-O) analysis and design is used to Object-Oriented Analysis and Design n n Object-oriented (O-O) analysis and design is used to build object-oriented programs This includes not only data but the instructions about operations that manipulate the data Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 34

Types of Object-Oriented Analysis and Design n There are three types of object-oriented analysis Types of Object-Oriented Analysis and Design n There are three types of object-oriented analysis and design: n n n Object-oriented analysis (OOA) Object-oriented design (OOD) The Unified Modeling Language (UML), a standardized object-oriented modeling language Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 35

Nature of Analysis and Design n n Structured analysis and design provides a systematic Nature of Analysis and Design n n Structured analysis and design provides a systematic approach to developing systems and is cyclic in nature Analysis and design errors detected in the later phases of the systems development life cycle cost more to fix than if detected in earlier phases Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 36

Alternate Methodologies n n Alternate methodologies are available for analyzing systems These include n Alternate Methodologies n n Alternate methodologies are available for analyzing systems These include n n n Prototyping ETHICS Project champions Soft Systems Methodology Multi-view Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 37