s от Systems Analysis and Design

s от Systems Analysis and Design lourih EDITION Joseph S. Valacich Washington State University Joey F. George Florida State University Jeffrey A. Hoffer University of Dayton Pearson Education International

Contents Preface 17 PARTI FOUNDATIONS FOR SYSTEMS DEVELOPMENT 28 Chapter 1 The Systems Development Environment 28 What Is Information Systems Analysis and Design? 30 Systems Analysis and Design: Core Concepts 30 Systems 32 Definition of a System and Its Parts 32 Important System Concepts 33 A Modern Approach to Systems Analysis and Design 36 Your Role in Systems Development 37 Types of Information Systems and Systems Development 38 Transaction Processing Systems 39 Management Information Systems 39 Decision Support Systems 40 Information Systems: An Overview 40 Developing Information Systems and the Systems Development Life Cycle 41 Phase 1: Systems Planning and Selection 43 Phase 2: Systems Analysis 43 Phase 3: Systems Design 44 Phase 4: Systems Implementation and Operation 44 Approaches to Development 46 Prototyping 47 Computer-Assisted Software Engineering (CASE) Tools 47 Joint Application Design 48 Rapid Application Development 48 Participatory Design 49 Agile Methodologies 50 Key Points Review 50 Key Terms Checkpoint 51 Review Questions 52 Problems and Exercises 53 Discussion Questions 53 Case Problems 53 Chapter 2 The Sources of Software 56 Introduction 57 Systems Acquisition 58 Outsourcing 58 Sources of Software 59 Choosing Off-the-Shelf Software 63 Reuse 67

10 Contents Key Points Review 70 Key Terms Checkpoint 70 Review Questions 71 Problems and Exercises 71 Field Exercises 71 Chapter 3 Managing the Information Systems Project 72 IUI Pine Valley Furniture Company Background 74 Managing the Information Systems Project 75 Initiating the Project 79 Planning the Project 83 Executing the Project 90 Closing Down the Project 93 Representing and Scheduling Project Plans 94 Representing Project Plans 96 Calculating Expected Time Durations Using PERT 96 ^ Constructing a Gantt Chart and Network Diagram at Pine Valley Furniture 97 Using Project Management Software 100 Establishing a Project Starting Date 101 Entering Tasks and Assigning Task Relationships 101 Selecting a Scheduling Method to Review Project Reports 102 Key Points Review 103 Key Terms Checkpoint 104 Review Questions 105 Problems and Exercises 105 Discussion Questions 107 Case Problems 108 Company Background 110 PART I! SYSTEMS PLANNING AND SELECTION 118 Chapter 4 Systems Planning and Selection 118 Identifying and Selecting Projects 120 The Process of Identifying and Selecting Information Systems Development Projects 120 Deliverables and Outcomes 123 Initiating and Planning Systems Development Projects 124 The Process of Initiating and Planning Systems Development Projects 124 Deliverables and Outcomes 125 Assessing Project Feasibility 126 Assessing Economic Feasibility 128

Contents 11 Assessing Other Feasibility Concerns 134 Building the Baseline Project Plan 135 Reviewing the Baseline Project Plan 141 PVF WebStore: Systems Planning and Selection 144 Internet Basics 144 Pine Valley Furniture WebStore 146 Key Points Review 149 Key Terms Checkpoint 150 Review Questions 151 Problems and Exercises 152 Discussion Questions 153 Case Problems 153 Initiating and Planning a Web-Based Customer Relationship Management System 155 PART III SYSTEMS ANALYSIS 160 Chapters Determining System Requirements 160 Performing Requirements Determination 162 The Process of Determining Requirements 162 Deliverables and Outcomes 163 Requirements Structuring 164 Traditional Methods for Determining Requirements 164 Interviewing and Listening 164 Directly Observing Users 169 Analyzing Procedures and Other Documents 170 Modern Methods for Determining System Requirements 173 Joint Application Design 174 Using Prototyping During Requirements Determination 177 Radical Methods for Determining System Requirements 178 Identifying Processes to Reengineer 179 Disruptive Technologies 180 W PVF WebStore: Determining System Requirements 181 System Layout and Navigation Characteristics 181 WebStore and Site Management System Capabilities 182 Customer and Inventory Information 183 System Prototype Evolution 183 Key Points Review 184 Key Terms Checkpoint 185 Review Questions 186 Problems and Exercises 186 Discussion Questions 186

12 Contents Case Problems 187 Determining Requirements for the Web-Based Customer Relationship Management System 188 Chapter 6 Structuring System Requirements: Process Modeling 192 Process Modeling 194 Modeling a System's Process 194 Deliverables and Outcomes 194 Data-Flow Diagramming Mechanics 195 Definitions and Symbols 196 Developing DFDs: An Example 198 Data-Flow Diagramming Rules 201 Decomposition of DFDs 202 Balancing DFDs 204 Using Data-Flow Diagramming in the Analysis Process 206 Guidelines for Drawing DFDs 206 Using DFDs as Analysis Tools 208 Using DFDs in Business Process Reengineering 209 Logic Modeling 211 Modeling Logic with Decision Tables 212 <f PVF WebStore: Process Modeling 215 Process Modeling for Pine Valley Furniture's WebStore 215 Key Points Review 217 Key Terms Checkpoint 218 Review Questions 219 Problems and Exercises 219 Discussion Questions 224 Case Problems 224 Process Modeling for the Web-Based Customer Relationship Management System 226 Chapter 7 Structuring System Requirements: Conceptual Data Modeling 230 Conceptual Data Modeling 232 The Process of Conceptual Data Modeling 233 Deliverables and Outcomes 233 Gathering Information for Conceptual Data Modeling 237 Introduction to Entity-Relationship Modeling 239 Entities 239 Attributes 241 Candidate Keys and Identifiers 241 Multivalued Attributes 242 Relationships 243

Contents 13 Conceptual Data Modeling and the E-R Model 243 Degree of a Relationship 244 Cardinalities in Relationships 245 An Example of Conceptual Data Modeling at Hoosier Burger 248 PVF WebStore: Conceptual Data Modeling 251 Conceptual Data Modeling for Pine Valley Furniture's WebStore 251 Selecting the Best Alternative Design Strategy 255 The Process of Selecting the Best Alternative Design Strategy 255 Generating Alternative Design Strategies 256 Developing Design Strategies for Hoosier Burger's New Inventory Control System 258 Selecting the Most Likely Alternative 260 Key Points Review 262 Key Terms Checkpoint 263 Review Questions 264 Problems and Exercises 264 Discussion Questions 267 Case Problems 267 Conceptual Data Modeling for the Web-Based Customer Relationship Management System 271 PART IV SYSTEMS DESIGN 274 r 8 Desiqninq the Human Interface 274 Designing Forms and Reports 276 The Process of Designing Forms and Reports 276 Deliverables and Outcomes 279 Formatting Forms and Reports 280 Designing Interfaces and Dialogues 288 The Process of Designing Interfaces and Dialogues 288 Deliverables and Outcomes 288 Designing Interfaces 289 Designing Dialogues 299 ( f' PVF WebStore: Designing the Human Interface 303 General Guidelines for Designing Web Interfaces 303 General Guidelines for Web Layouts 304 Designing the Human Interface at Pine Valley Furniture 305 Menu-Driven Navigation with Cookie Crumbs 306 Lightweight Graphics 306 Forms and Data Integrity 307 Template-Based HTML 307

14 Contents Key Points Review 307 Key Terms Checkpoint 308 Review Questions 309 Problems and Exercises 309 Discussion Questions 310 Case Problems 310 Designing the Human Interface for the Customer Relationship Management System 312 Chapter 9 Designing Databases 316 Database Design 318 The Process of Database Design 318 Deliverables and Outcomes 320 Relational Database Model 323 Well-Structured Relations 324 Normalization 325 Rules of Normalization 325 Functional Dependence and Primary Keys 326 Second Normal Form 326 Third Normal Form 327 Transforming E-R Diagrams into Relations 328 Represent Entities 329 Represent Relationships 330 Summary of Transforming E-R Diagrams to Relations 332 Merging Relations 333 An Example of Merging Relations 333 View Integration Problems 334 Logical Database Design for Hoosier Burger 335 Physical File and Database Design 337 Designing Fields 338 Choosing Data Types 338 Controlling Data Integrity 340 Designing Physical Tables 341 Arranging Table Rows 343 Designing Controls for Files 347 Physical Database Design for Hoosier Burger 349 PVF WebStore: Designing Databases 351 Designing Databases for Pine Valley Furniture's WebStore 351 Key Points Review 353 Key Terms Checkpoint 355 Review Questions 356 Problems and Exercises 357 Discussion Questions 358

Contents 15 Case Problems 359 Designing the Relational Database for the Customer Relationship Management System 360 PARTV SYSTEMS IMPLEMENTATION AND OPERATION 362 rfer 10 Systems Implementation and Operation 362 Systems Implementation and Operation 364 The Processes of Coding, Testing, and Installation 365 Deliverables and Outcomes from Coding, Testing, and Installation 365 The Processes of Documenting the System, Training Users, and Supporting Users 366 Deliverables and Outcomes from Documenting the System, Training Users, and Supporting Users 366 The Process of Maintaining Information Systems 367 Deliverables and Outcomes from Maintaining Information Systems 368 Software Application Testing 369 Seven Different Types of Tests 369 The Testing Process 371 Acceptance Testing by Users 373 Installation 374 Planning Installation 374 Documenting the System 377 User Documentation 378 Preparing User Documentation 380 Training and Supporting Users 380 Training Information System Users 380 Supporting Information System Users 382 Support Issues for the Analyst to Consider 384 Why Implementation Sometimes Fails 385 Project Closedown 386 Conducting Systems Maintenance 387 Types of Maintenance 387 The Cost of Maintenance 388 Measuring Maintenance Effectiveness 389 Controlling Maintenance Requests 390 Configuration Management 391 Role of Automated Development Tools in Maintenance 392 _ Web Site Maintenance 392 Maintaining an Information System at Pine Valley Furniture 393 PVF WebStore: Systems Implementation and Operation 395 Systems Implementation and Operation for Pine Valley Furniture's WebStore 395

16 Contents Key Points Review 397 Key Terms Checkpoint 399 Review Questions 400 Problems and Exercises 401 Discussion Questions 401 Case Problems 402 Designing a Testing Plan for the Customer Relationship Management System 403 Appendix A Object-Oriented Analysis and Design 406 The Object-Oriented Modeling Approach 406 Use-Case Modeling 407 Object Modeling: Class Diagrams 410 Representing Associations 411 Representing Generalization 413 Representing Aggregation 415 Dynamic Modeling: State Diagrams 416 Dynamic Modeling: Sequence Diagrams 417 Designing a Use Case with a Sequence Diagram 419 Moving to Design 420 Key Points Review 421 Key Terms Checkpoint 422 Review Questions 423 Problems and Exercises 423 Appendix В Agile Methodologies 425 The Trend to Agile Methodologies 425 Agile Methodologies 426 extreme Programming 428 The Heart of the Systems Development Process 429 Requirements Determination 430 Design Specifications 433 Implementation 435 Key Points Review 435 Key Terms Checkpoint 436 Review Questions 436 Problems and Exercises 436 References 437 Glossary of Acronyms 442 Glossary of Terms 444 Index 449 Photo Credits 459