1 senn, information technology, 3 rd edition © 2004 pearson prentice hall james a. senn’s...

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.

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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.