Information System Development

Discovering Computers 2011 Living in a Digital World

Objectives OverviewObjectives Overview Discuss the importance of project management project management, Define system development Identify the guidelines for feasibility assessment, and list the system system development documentation, and data development phases g and information gathering g techniques Explain the activities Discuss the purpose of the Describe the various tools performed in the planning activities performed in the used in process modeling phase analysis phase analysis phaseSee Page 619 Discovering Computers 2011: Living in a Digital World 2for Detailed Objectives Chapter 12

Objectives OverviewObjectives Overview Recognize the develop Recognize the develop Describe the various D ib h i Explain the activities E l i h i ii programs activity is tools used in object performed in the part of system modeling design phase development Discuss the purpose of Discuss the purpose of Discuss the activities the activities performed in the performed in the implementation phase implementation phase operation, support, and operation support and security phaseSee Page 619 Discovering Computers 2011: Living in a Digital World 3for Detailed Objectives Chapter 12

What is System Development?What is System Development? System development is a set of activities used to build an information system used to build an information system An information system (IS) is a System development A system is a set of collection of activities are grouped components that components that hardware, software, hardware software into phases, and is into phases and is interact to achieve a data, people, and called the system common goal procedures that work development life together to produce cycle (SDLC) quality informationPage 620 Discovering Computers 2011: Living in a Digital World 4 Chapter 12

What is System Development?What is System Development?Pages 620 – 621 Discovering Computers 2011: Living in a Digital World 5Figure 12‐1 Chapter 12

What is System Development?What is System Development?• System development should follow three general g guidelines: Group activities or tasks into phases p p Involve users Involve users Define standards f d dPage 621 Discovering Computers 2011: Living in a Digital World 6 Chapter 12

What is System Development?What is System Development?• System development should involve representatives from each department in which the proposed system will be usedPage 622 Discovering Computers 2011: Living in a Digital World 7Figure 12‐2 Chapter 12

What is System Development?What is System Development?• Project management is the process of planning, scheduling, and then controlling the activities during system development• To plan and schedule a project efficiently, the project leader identifies: Required Required Time estimates Time estimates Project scope activities for each activity Activities that Cost estimates Order of can take place at for each activity for each activity activities the same time hPage 623 Discovering Computers 2011: Living in a Digital World 8 Chapter 12

What is System Development?What is System Development? A popular tool used to plan used to plan and schedule the time relationships among project activities is a Gantt chart Click to view Web Link, click Chapter 12, Click Web Link from left navigation navigation, then click Gantt Charts below Chapter 12Page 623 Discovering Computers 2011: Living in a Digital World 9Figure 12‐3a Chapter 12

What is System Development?What is System Development? A PERT chart also can be used for planning and scheduling timescheduling time Click to view Web Link, click Chapter 12, Click Web Link from left navigation navigation, then click PERT Charts below Chapter 12Page 624 Discovering Computers 2011: Living in a Digital World 10Figure 12‐3b Chapter 12

What is System Development?What is System Development?• Feasibility is a measure of how suitable the p y development of a system will be to the organization Operational Schedule Technical Economic feasibility feasibility feasibility feasibilityPages 624 ‐ 625 Discovering Computers 2011: Living in a Digital World 11 Chapter 12

What is System Development?What is System Development?• Documentation is the collection and summarization of data and information – A project notebook contains all documentation for a single project single project• Users and IT professionals refer to existing documentation when working with and modifying d i h ki ih d dif i current systemsPage 625 Discovering Computers 2011: Living in a Digital World 12 Chapter 12

What is System Development?What is System Development?• During system development, members of the project team gather data and information using several techniques Review Observe Surveydocumentation Interview I i JAD Sessions JAD S i Research R hPages 625 – 626 Discovering Computers 2011: Living in a Digital World 13Figure 12‐4 Chapter 12

Who Initiates a System Development Project? l j ?A user may request a new or modified systemOrganizations may want to improve hardware, software, or other technologySituations beyond an organization’s control might require a changeManagement might mandate a changeA user may request a new or modified information system using a request for system services or a project requestfor system services or a project requestPage 626 Discovering Computers 2011: Living in a Digital World 14 Chapter 12

Who Initiates a System Development Project? l j ?Page 627 Discovering Computers 2011: Living in a Digital World 15Figure 12‐5 Chapter 12

Planning PhasePlanning Phase• The planning phase for a project begins when the g p j q steering committee receives a project request• Four major activities are performed: Review and Form a project Prioritize the Allocate approve the development project requests resources project requests teamPage 628 Discovering Computers 2011: Living in a Digital World 16 Chapter 12

Analysis PhaseAnalysis Phase• The analysis phase consists of two major activities: Conduct a preliminary Perform detailed investigation analysis • Determines and • Study how the current defines the exact defines the exact system works system works nature of the problem • Determine the users’ or improvement p wants, needs, and wants, needs, and • Interview the user who requirements submitted the request • Recommend a solutionPages 629 ‐ 631 Discovering Computers 2011: Living in a Digital World 17 Chapter 12

Analysis PhaseAnalysis Phase Click to view Web Link, click Chapter 12, Click Web Link from left navigation navigation, then click Feasibility Study below Chapter 12Pages 629 – 630 Discovering Computers 2011: Living in a Digital World 18Figure 12‐6 Chapter 12

Analysis PhaseAnalysis Phase• Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs Entity Entity‐ Data flow relationship diagrams diagrams Project Click to view Web Link, click Chapter 12, Click Web dictionary Link from left navigation navigation, then click Process Modeling below Chapter 12Page 631 Discovering Computers 2011: Living in a Digital World 19 Chapter 12

Analysis PhaseAnalysis Phase • An entity‐relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system • Entities are objects in the system that have dataPage 632 Discovering Computers 2011: Living in a Digital World 20Figure 12‐7 Chapter 12

Analysis PhaseAnalysis Phase • A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system – Data flows – Processes – Data stores – SourcesPage 632 Discovering Computers 2011: Living in a Digital World 21Figure 12‐8 Chapter 12

Analysis PhaseAnalysis Phase• The project dictionary contains all the p j documentation and deliverables of a project• Structured English is a style of writing that style of writing that describes the steps in a processPage 633 Discovering Computers 2011: Living in a Digital World 22Figure 12‐9 Chapter 12

Analysis PhaseAnalysis Phase A decision table is a table that y lists a variety of conditions and the actions that correspond to each condition A decision tree also shows , conditions and actions, but it shows them graphicallyPage 633 Discovering Computers 2011: Living in a Digital World 23 Chapter 12

Analysis PhaseAnalysis Phase Decision table Decision treePage 633 Discovering Computers 2011: Living in a Digital World 24Figures 12‐10 – 12‐11 Chapter 12

Analysis PhaseAnalysis Phase• The data dictionary stores the data item’s name, p description, and other details about each data itemPage 634 Discovering Computers 2011: Living in a Digital World 25Figure 12‐12 Chapter 12

Analysis PhaseAnalysis Phase• Object modeling combines the data with the processes that act on that data into a single unit, called an object• UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development – UML includes 13 different diagrams – Two diagrams include: g Use case Use case Class diagram Click to view Web Link, click Chapter 12, Click Web diagram Link from left navigation navigation, then click UML below Chapter 12Page 634 Discovering Computers 2011: Living in a Digital World 26 Chapter 12

Analysis PhaseAnalysis Phase • A use case diagram graphically shows how actors (users) interact with the information system • Diagrams are considered easy to understandPage 634 Discovering Computers 2011: Living in a Digital World 27Figure 12‐13 Chapter 12

Analysis PhaseAnalysis Phase • A l A class diagram di graphically shows classes and subclasses classes and subclasses in a system • Each class can have one Each class can have one or more subclasses • Subclasses use Subclasses use inheritance to inherit methods and attributes methods and attributes of higher levelsPage 635 Discovering Computers 2011: Living in a Digital World 28Figure 12‐14 Chapter 12

Analysis PhaseAnalysis Phase• The system proposal assesses the feasibility of each alternative solution• The steering committee discusses the system proposal and decides which alternative to pursue proposal and decides which alternative to pursue Packaged Custom Outsourcing software software Click to view Web Link, click Chapter 12, Click Web navigation, Link from left navigation then click Vertical Market Software below Chapter 12Pages 635 ‐ 636 Discovering Computers 2011: Living in a Digital World 29 Chapter 12

Design PhaseDesign Phase• The design phase consists of two major activities Develop all of the Acquire hardware details of the new and software or modified information systemPage 638 Discovering Computers 2011: Living in a Digital World 30 Chapter 12

Design PhaseDesign Phase• To acquire the necessary hardware and software: Solicit vendor Make a decision• Use research proposals • Various techniques q techniques such as are used to e‐zines • RFQ, RFP, or RFI is determine the best • Systems analyst sent to potential proposal makes vendors or VARs recommendation to steering committee steering committee Identify technical Test and evaluate specifications vendor proposals Click to view Web Link, click Chapter 12, Click Web Link from left navigation navigation, then click E-Zines below Chapter 12Pages 638 ‐ 640 Discovering Computers 2011: Living in a Digital World 31 Chapter 12

Design PhaseDesign Phase• The next step is to develop detailed design p specifications – Sometimes called a physical design Input and Database Program output design design designPage 640 Discovering Computers 2011: Living in a Digital World 32 Chapter 12

Design PhaseDesign Phase• Systems analysts typically develop two types of g p p designs for each input and output Mockup Layout chartPage 641 Discovering Computers 2011: Living in a Digital World 33Figures 12‐18 – 12‐19 Chapter 12

Design PhaseDesign Phase• A prototype (proof of concept) is a working model p p y of the proposed system – Prototypes have inadequate or missing documentation – Users tend to embrace the prototype as a final system Users tend to embrace the prototype as a final system – Should not eliminate or replace activitiesPages 641 ‐ 642 Discovering Computers 2011: Living in a Digital World 34 Chapter 12

Design PhaseDesign Phase• Computer‐aided software engineering (CASE) g pp tools are designed to support one or more activities of system development• CASE tools sometimes contain the following tools: CASE tools sometimes contain the following tools: Project Project Graphics h Prototyping repository Quality Code Click to view Web Link, click Chapter 12, Click Web Housekeeping Link from left navigation navigation, assurance generator g then click CASE Tools below Chapter 12Page 642 Discovering Computers 2011: Living in a Digital World 35 Chapter 12

Design PhaseDesign PhasePage 642 Discovering Computers 2011: Living in a Digital World 36Figure 12‐20 Chapter 12

Design PhaseDesign Phase• Many people should review the detailed design p specifications• An inspection is a formal review of any system development deliverable development deliverable – A team examines the deliverables to identify errorsPage 642 Discovering Computers 2011: Living in a Digital World 37 Chapter 12

Implementation PhaseImplementation Phase• The purpose of the implementation phase is to y construct the new or modified system and then deliver it Install and Install and Convert to Convert to Develop test the new Train users the new programs system systemPage 643 Discovering Computers 2011: Living in a Digital World 38 Chapter 12

Implementation PhaseImplementation Phase• The program development life cycle follows these p steps: • Analyze the requirements Analyze the requirements 1 2 • Design the solution g 3 • Validate the design 4 • Implement the design 5 • T t th Test the solution l ti 6 • Document the solutionPage 643 Discovering Computers 2011: Living in a Digital World 39 Chapter 12

Implementation PhaseImplementation Phase• Various tests should be performed on the new y system Integration Acceptance Unit test Systems test y test test • Verifies that • Verifies that • Verifies that • Checks the each each all programs all programs an an new system new system individual in an application to ensure program or application works with that it works object works object works work work other other with actual with actual by itself together applications data properlyPage 644 Discovering Computers 2011: Living in a Digital World 40 Chapter 12

Implementation PhaseImplementation Phase• Training involves showing users exactly how they will use the new hardware and software in the system – One‐on‐one sessions One‐on‐one sessions – Classroom‐style lectures – Web‐based trainingPage 644 Discovering Computers 2011: Living in a Digital World 41Figure 12‐21 Chapter 12

Implementation PhaseImplementation Phase• One or more of four conversion strategies can be g y used to change from the old system to the new systemPages 644 – 645 Discovering Computers 2011: Living in a Digital World 42Figure 12‐22 Chapter 12

Operation, Support, and Security PhaseOperation, Support, and Security Phase• The purpose of the operation, support, and security phase is to provide ongoing assistance for yp p g g an information system and its users after the system is implemented system is implemented Perform Monitor Assess system Assess system maintenance system security activities performance Click to view Web Link, click Chapter 12, Click Web navigation, Link from left navigation then click Chief Security Officer below Chapter 12Pages 645 ‐ 646 Discovering Computers 2011: Living in a Digital World 43 Chapter 12

Operation, Support, and Security PhaseOperation, Support, and Security Phase• A computer security plan should do the following: For each risk, Identify all identify the Identify all security risks safeguards that information that may cause that may cause exist to detect, exist to detect assets of an an information prevent, and organization asset loss recover from a lossPage 646 Discovering Computers 2011: Living in a Digital World 44 Chapter 12

Video: Create a Hidden Operating SystemVideo: Create a Hidden Operating System CLICK TO START CLICK TO START Discovering Computers 2011: Living in a Digital World 45 Chapter 12

Summary System Guidelines for development d l t system t phases development Activities Activities that occur performed during during system during system each system development development phase p pPage 647 Discovering Computers 2011: Living in a Digital World 46 Chapter 12

Discovering Computers 2011 Living in a Digital World Chapter 12 Complete

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Information System Development

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