1 senn, information technology, 3 rd edition © 2004 pearson prentice hall james a. senn’s...
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1 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
James A. Senn’sInformation Technology, 3rd Edition
Chapter 11
Creating Enterprise Applications
2 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Objectives
• Describe the principal functions and roles of a system analyst.
• Identify the characteristics of shared systems.
• Discuss the changing process for developing information systems applications.
3 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Objectives (Continued)
• Describe the tools and techniques available to system analysts for collecting data and developing IT applications.
• Summarize the purpose and characteristics of unified modeling language (UML).
• Explain the roles of the four types of IT systems development professionals.
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Developing Open Shared SystemsDevelopment Alternatives
• Build the application itself.
• Purchase a prewritten application.
• Contract out the application development.
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Developing Open Shared SystemsOpen Systems for Sharing
• Open System: A software system that performs on different computer and communications hardware.
• Interoperability: The perfect exchange of data and information in all forms (data, text, sound, and image, including animation) between the individual components of an application (hardware, software, network).
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Developing Open Shared SystemsShifting Development Model
• Craft Approach
• Assembly Approach
• Object: A component that contains data about itself and how it is to be processed.
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Developing Open Shared SystemsBuilding IT with Components
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The System Analyst’s Tools and TechniquesDefinition
• Systems Analyst: The IT professional responsible for working with users to determine a system’s requirements and for describing the features needed in the system.
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The System Analyst’s Tools and TechniquesData Collection Techniques
• Interviews– Structured Interview: An interview in which
the questions are prepared in advance and each interviewee is asked the same set of questions.
– Unstructured Interview: An interview in which the questions may be prepared in advance, but follow-up questions vary, depending on the interviewees’ background and answer.
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The System Analyst’s Tools and TechniquesData Collection Techniques (Continued)
• Questionnaire: A sheet of questions used to collect facts and opinions from a group of people.
• Document Examination/Record Inspection: The review of company documents about a system or opportunity under investigation.
• Observation: The process of watching an activity take place to collect information about that activity.
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The System Analyst’s Tools and TechniquesData Collection Techniques (Continued)
• Sampling: The process of collecting data and information at prescribed intervals.
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The System Analyst’s Tools and TechniquesSystem Flowcharts
• System Flowcharts: A graphical description of a business process or procedure using standard symbols to show decision logic.
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The System Analyst’s Tools and TechniquesSystem Flowcharts (Continued)
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The System Analyst’s Tools and Techniques Dataflow Diagram
• Dataflow Diagram (DFD): A chart showing the movement of data through a system.– DFD Levels
• Leveling: The process of exploding processes in a dataflow diagram to show more detail.
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The System Analyst’s Tools and Techniques Dataflow Diagram (Continued)
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The System Analyst’s Tools and Techniques Dataflow Diagram (Continued)
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The System Analyst’s Tools and Techniques Data Dictionaries
• Data Dictionary/Repository: A catalog that lists and describes all the types of data flowing through a system. Composed of data elements and a data structure.
• Data Element: The component of a data dictionary that includes data names, alternate names, and length allowances.
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The System Analyst’s Tools and Techniques Data Dictionaries (Continued)
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The System Analyst’s Tools and Techniques Data Dictionaries (Continued)
• Data Structure: The set of data elements used together and the name that collectively identifies the set.
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Computed-Aided Systems Engineering (CASE)Definition
• Computed-Aided Systems Engineering/Computer-Aided Software Engineering (CASE): A set of tools used in systems development to improve the consistency and quality of the system while automating many of the most tedious and time-consuming systems tasks.– Charting and Diagramming Tools– Centralized Information Repository– Interface Generators– Code Generators– Project Management Tools
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Computed-Aided Systems Engineering (CASE)Definition (Continued)
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Computed-Aided Systems Engineering (CASE)Front-End, Back-End, and Integrated CASE
• Front-End CASE Tool: A CASE tool that automates the early (front-end) activities in systems development.
• Back-End CASE Tool: A CASE tool that automates the later (back-end) activities in systems development.
• Integrated CASE (I-CASE) Tool: A CASE tool that spans activities throughout the entire systems development life cycle.
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Computed-Aided Systems Engineering (CASE)Front-End, Back-End, and Integrated CASE (Continued)
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Unified Modeling LanguageDefinition
• Unified Modeling Language (UML): The standard vehicle for visualizing, describing,and documenting the details of an IT application.
• Actor: Anyone or anything that will interact with the application.
• Activity Diagram: Shows the flow of control in an application.
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Unified Modeling LanguageDefinition (Continued)
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Unified Modeling LanguageDefinition (Continued)
• Use Case Diagram: Provides context for the system, illustrating the actors, the use cases, and the flow or interaction between use cases and actors.– Use Case: Identifies the sequence of
activities performed for an actor.
• Use Case Description: Describes the use case in ordinary language, including its identifying name and actors.
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Unified Modeling LanguageDefinition (Continued)
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Unified Modeling LanguageDefinition (Continued)
• Class Diagram: Describes an object class, including the class name, attributes, and methods.
• Other UML Diagrams– Sequence Diagram– State Transition Diagram– Component Diagram
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Unified Modeling LanguageDefinition (Continued)
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IT Development PersonnelThe Systems Analyst: The Key Roles
• Change Agent: A person who acts as a catalyst for change.
• Professional Skills– Problem Solving– Outcome Thinking– Creativity– Meeting Skills– Communication Skills
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IT Development PersonnelThe Systems Analyst: The Key Roles
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IT Development PersonnelThe Chief Information Officer
• Chief Information Officer (CIO)/IT Director/Director of Information Systems: The person given the responsibility of managing and developing the firm’s information technology capabilities.
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IT Development PersonnelThe Chief Information Officer (Continued)
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IT Development PersonnelComputer Programmers
• Computer Programmers– Responsible for turning detailed
specifications into computer software.– Responsible for documenting the program.
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IT Development PersonnelSystem Contractors
• System Contractor: An outside person or firm that contracts with a company to develop IT applications.
• System Integrator: A type of systems contractor who is retained to take responsibility for acquiring hardware, software and network capacity for an application, as well as for implementing the application.