Transcript Discovering Computers Fundamentals 3rd Edition
System Development Information System Development
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Learning Outcomes
Students should be able to… Discuss the importance of project management, feasibility assessment, documentation, data and information gathering techniques, and information systems security during system development Discuss the purpose of each phase in the system development cycle 2
The System Development Life Cycle
What is an information system (IS) ?
Hardware, software, data, people, and procedures that work together to produce quality information
Procedures People Data Hardw are Softw are
1996 2007 System —Set of components that interact to achieve common goal Businesses use many types of systems 3
The System Development Life Cycle
What are the phases of the system development life cycle ?
Phase 1. Planning
Review project requests Prioritize project requests Allocate resources Form project development team
Phase 2. Analysis
Conduct preliminary investigation Perform detailed analysis activities: Study current system Determine user requirements Recommend solution
Phase 3. Design
Acquire hardware and software, if necessary Develop details of system
Phase 5. Operating, Support, and Security
Perform maintenance activities Monitor system performance Assess system security
Phase 4. Implementation
Develop programs, if necessary Install and test new system Train users Convert to new system
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The System Development Life Cycle
What are guidelines for system development?
Arrange tasks into phases (groups of activities) Involve users (anyone for whom system is being built) Develop clearly defined follow) standards (procedures company expects employees to 5
The System Development Life Cycle
Who participates in the system development life cycle?
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The System Development Life Cycle
What is a systems analyst ? A person!!!
A person(s) playing the “role” of systems analyst is: Responsible for designing and developing information systems the “End Users” (stakeholders) primary contact person 7
The System Development Life Cycle
What is the project team ?
Formed to work on a project from beginning to end Consists of users, systems analyst, and other IT professionals Project leader
— one member of the team who manages and controls the project budget and schedule
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The System Development Life Cycle
What is project management ?
Process of planning, scheduling, and controlling activities during system development cycle
Project leader identifies elements for project Goal, objectives, and expectations, collectively called scope Cost estimates for each activity Required activities & roles played to fulfill the activities Order of activities Time estimates for each activity Activities that can take place at same time 9
The System Development Life Cycle
What is a Gantt chart ?
Popular tool used to plan and schedule time relationships among project activities 10
The System Development Life Cycle
What is feasibility ?
Operational feasibility Measure of how suitable system development will be to the company Four feasibility tests: Schedule feasibility Economic feasibility (also called cost/benefit feasibility) Technical feasibility 11
The System Development Life Cycle
What is documentation ?
Collection and summarization of data and information Includes reports, diagrams, programs, and other deliverables Online Help too!!!
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The System Development Life Cycle
What are six data and information gathering techniques?
Review documentation
Observe Questionnaire Interview Joint-application design (JAD) session Research JAD Session in Progress 13
The System Development Life Cycle
What are some reasons to create or modify an information system?
To correct problem in existing system To improve existing system Outside group may mandate change Competition can lead to change 14
The System Development Life Cycle
What is the planning phase ?
Begins when steering committee receives project request Steering committee — decision-making body for the company Review and approve project requests Function of committee: Prioritize project requests Allocate resources Form project development team for each approved project 15
The System Development Life Cycle
What is the analysis phase ?
Conduct preliminary investigation, also called feasibility study Perform detailed analysis feasibility tests: Economic feasibility Four Schedule feasibility Technical feasibility Operational feasibility 16
The System Development Life Cycle
What are possible solutions?
Buy packaged software prewritten software available for purchase — Write own custom software request — software developed at user’s Horizontal market software
—meets needs of many companies
Vertical market software
— designed for particular industry
Outsource — have outside source develop software 17
The System Development Life Cycle
What is the design phase ?
Acquire hardware and software Develop all details of new or modified information system Database design Includes several activities Input and output design Program design
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The System Development Life Cycle
What is a prototype ?
A working model of the proposed system Mockup is a sample of input and/or output: 19
The System Development Life Cycle
What is computer-aided software engineering (CASE) ?
Software tools designed to support activities of the system development life cycle
• •
Two popular Examples:
Microsoft’s Visual Studio Eclipse
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The System Development Life Cycle
What is the implementation phase ?
Purpose is to construct, or build, new or modified system and then deliver it to users Convert to new system Train users Install and test new system Develop programs 21
The System Development Life Cycle
What are the four types of tests performed by system developers?
Unit Test Verifies each individual program works by itself Integration Test Verifies application works with other applications Systems test Verifies all programs in the application work together Acceptance Test Verifies the new system works with actual data 22
The System Development Life Cycle
What are conversion strategies?
Used to switch from old system to new system 23
The System Development Life Cycle
What is the operation, support, and security phase ?
Provides ongoing assistance after system is implemented Perform maintenance activities Monitor system performance Assess system security 24
The System Development Life Cycle
Video: A Tour of Lucasfilm’s Data Center CLICK TO START
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Programming Languages What is a computer program (software) ?
Set of instructions that directs the computer to perform tasks
Programming language
—used to communicate instructions
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Programming Languages…”in the beginning” What is machine language ?
Only language computer directly recognizes
Uses a series of binary digits (1s and 0s) with a combination of numbers and letters that represent binary digits 27
Programming Languages…a wee-bit newer What is assembly language ?
Instructions made up of symbolic instruction codes codes , meaningful abbreviations and Source program contains code to be converted to machine language 28
Programming Languages…1960’s until now What is COBOL ?
COmmon Business-Oriented Language
Designed for business applications
English-like statements make code easy to read, write, and maintain 29
Programming Languages…many more today What are C, C++, C#, Visual Basic, Java, JavaScript, Perl, PerlScript, PHP, Ruby on Rails, Cold Fusion…
Powerful languages
Requires professional programming skills (or at least training of yourself) 30
Programming Languages What is a compiler ?
A program (software) that converts the entire source program into machine language before executing it 31
Programming Languages What is an interpreter ?
A program that translates and executes one program code statement at a time Does not produce an object program Browsers do this!
(For example, Firefox or Internet Explorer) 32
Programming Languages…many, many more What are other available programming languages?
ADA ALGOL APL BASIC FORTH FORTRAN HYPERTALK PASCAL LISP PILOT LOGO PL/1 MODULA-2 PROLOG SMALLTALK 33
Programming Languages What is an application generator ?
Program that creates source code or machine code from a specification Consists of a report writer, a form, and menu generator 34
Programming Languages What is HTML
(Hypertext Markup Language)?
Used to create Web pages Source Code: WYSIWYG (“wiz-e-wig”) What You See is What You Get: View -> Source 35
Programming Languages What is a scripting language?
Programming language used to allow Web pages to be more “powerful” (do more things) Examples:
JavaScript VBScript Perl 36
Programming Languages What is dynamic HTML (DHTML) ?
Enhanced version of HTML which allows developers to include more graphical interest and interactivity on Web pages 37
Programming Languages
What are XML and WML ?
XML (Extensible Markup Language) allows developers to create customized tags Office 2007 default document Format is XML: .docx, .xlsx, .pptx
Server sends entire record to client, enabling client to do much of processing without going back to the server
WML (Wireless Markup Language) allows developers to design pages specifically for microbrowsers Many PDAs and smart phones use WML as their markup language 38
Programming Languages What is Web page authoring software ?
Creates sophisticated Web pages without using HTML This software generates (creates) the HTML code for you
• Dreamweaver • Expression Web • Flash
Examples of Web page authoring software
• Silverlight
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Companies on the Cutting Edge
Video: Electronic Arts Going Mobile CLICK TO START
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