Ebook Modern systems analysis and design (Eighth edition): Part 2

Ebook Modern systems analysis and design (Eighth edition): Part 2 include of the following contents: Chapter 9 designing databases, chapter 10 designing forms and reports, chapter 11 designing interfaces and dialogues, chapter 12 designing distributed and internet systems, chapter 13 system implementation, chapter 14 maintaining information systems.
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Ebook Modern systems analysis and design (Eighth edition): Part 2 Part Four Design Chapter 9 Chapter 11 Designing Databases Designing Interfaces and Dialogues Chapter 10 Chapter 12 Designing Forms and Reports Designing Distributed and Internet Systems 309 Overview Part Four Design The focus of Part Four is system design, which is often on business forms, visual display screens, printed docu- the first phase of the systems development life cycle, ments, and other kinds of media. Fortunately, there has the phase in which you and the user develop a concrete been considerable research on how to present data to understanding of how the system will operate. The ac- users, and Chapter 10 summarizes and illustrates the most tivities within design are not necessarily sequential. For useful of these guidelines. Chapter 11 is closely related to example, the design of data, system inputs and outputs, Chapter 10 and addresses principles you should follow and interfaces interact, allowing you to identify flaws and in tying all the system inputs and outputs together into missing elements. This means that the project dictionary an overall pattern of interaction between users and the or CASE repository becomes an active and evolving com- system. System interfaces and dialogues form a conversa- ponent of systems development management during de- tion that provides user access to and navigation between sign. It is only when each design element is consistent each system function. Chapter 11 focuses on providing with others and each one is satisfactory to the end user specifications for designing effective system interfaces that you know that the design phase is complete. and dialogues and a technique for representing these Data are a core system element, and data design designs called dialogue diagramming. and structure are studied in all systems development For traditional development efforts, before devel- methodologies. You have seen how data flow diagrams opers can begin the implementation process, questions (DFDs) and entity-relationship (E-R) diagrams (as well about multiple users, multiple platforms, and program as use cases and class diagrams from the object-oriented and data distribution have to be considered. The extent material at the end of prior chapters) are used to depict to which the system is Internet-based also has an impact the data requirements of a system. These diagrams are on numerous design issues. The focus of Chapter 12 is flexible and allow considerable latitude in how you on the intricacies of designing distributed and Internet represent data. For example, you can use one or many systems. data stores with a process in a DFD. E-R diagrams pro- The deliverables of design include detailed, func- vide more structure, but an entity can still be either very tional specifications for system inputs, outputs, inter- detailed or rather aggregate. When designing databases, faces, dialogues, and databases. Often these elements you define data in its most fundamental form, called are represented in prototypes, or working versions. normalized data. Normalization is a well-defined method The project dictionary or CASE repository is updated of identifying relationships between each data attribute to include each form, report, interface, dialogue, and and representing all the data so that they cannot logi- relation design. Due to considerable user involvement in cally be broken down into more detail. The goal is to rid reviewing prototypes and specifications during design, the data design of unwanted anomalies that would make and due to the fact that activities within design can be a database susceptible to errors and inefficiencies. This is scheduled with considerable overlap in the project base- the topic of Chapter 9. line plan, a formal review milestone or walk-through In Chapter 10, you will learn the principles and often does not occur after each activity. If prototyping guidelines for usable system inputs and outputs. Your is not done, however, you should conduct a formal walk- overall goal in formatting the presentation of data to through at the completion of the system design phase. users should be usability: helping users of all types to use All of the chapters in Part Four conclude with a the system efficiently, accurately, and with satisfaction. Petrie Electronics case. These cases illustrate numerous The achievement of these goals can be greatly improved relevant design activities for an ongoing systems develop- if you follow certain guidelines when presenting data ment project within the company. 310 Chapter Designing Databases 9 Learning objectives After studying this chapter, you should be able to 9.5 describe physical database design concepts 9.1 describe the database design process, its including choosing storage formats for fields in outcomes, and the relational database model; database tables, translating well-structured relations into efficient database tables, explaining 9.2 describe normalization and the rules for second when to use different types of file organizations to and third normal form; store computer files, and describing the purpose of 9.3 transform an entity-relationship (E-R) diagr ...