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Chapter 11 Information System Development and Programming Languages. Chapter 11 Objectives. Next. Discuss the importance of project management, feasibility assessment, documentation, data and information gathering techniques, and information systems security during system development.
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Chapter 11 Information System Development and Programming Languages
Chapter 11 Objectives Next Discuss the importance of project management, feasibility assessment, documentation, data and information gathering techniques, and information systems security during system development List other programming languages and other program development tools Describe various ways to develop Web pages Discuss the purpose of each phase in the system development cycle List the six steps in the program development cycle Differentiate between low-level languages and procedural languages Explain the basic control structures used in designing solutions to programming problems Identify the benefits of object-oriented programming languages and program development tools
The System Development Life Cycle Next • What is an information system (IS)? Hardware, software, data, people, and procedures that work together to produce quality information System—Set of components that interact to achieve common goal Businesses use many types of systems p. 406
The System Development Life Cycle Next • What are the phases of the system development cycle? Phase 2. Analysis • Conduct preliminary investigation • Perform detailed analysis activities: • Study current system • Determine user requirements • Recommend solution Phase 1. Planning Phase 3. Design • Review project requests • Prioritize project requests • Allocate resources • Form project development team • Acquire hardware and software, if necessary • Develop details of system Phase 4. Implementation Phase 5. Operating, Support, and Security • Develop programs, if necessary • Install and test new system • Train users • Convert to new system • Perform maintenance activities • Monitor system performance • Assess system security p. 406 Fig. 11-1
The System Development Life Cycle Next • 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 standards (procedures company expects employees to follow) p. 407
The System Development Life Cycle Next • Who participates in the system development life cycle? p. 407 Fig. 11-2
The System Development Life Cycle Next • What is a systems analyst? Responsible for designing and developing information system Users’ primary contact person p. 407
The System Development Life Cycle Next • What is theproject team? Formed to work on 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 project budget and schedule p. 408
The System Development Life Cycle Next • 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 Required activities Time estimates for each activity Cost estimates for each activity Order of activities Activities that can take place at same time p. 408
The System Development Life Cycle Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click PERT Chartsbelow Chapter 11 Next • What is a Gantt chart? • Popular tool used to plan and schedule time relationships among project activities p. 409 Fig. 11-3
The System Development Life Cycle Next • 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 p. 409
The System Development Life Cycle Next • What is documentation? Collection and summarization of data and information Includes reports, diagrams, programs, and other deliverables p. 409
The System Development Life Cycle Next • What are six data and information gathering techniques? • Review documentation • Observe • Questionnaire • Interview • Joint-application design (JAD) session • Research p. 410 Fig. 11-4
The System Development Life Cycle Next • 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 p. 410
The System Development Life Cycle Next • What is a request for system services? • Formal request for new or modified information system • Also called project request p. 411 Fig. 11-5
The System Development Life Cycle Next • What is the planning phase? Begins when steering committee receives project request Steering committee—decision-making body for the company Function of committee: Review and approve project requests Prioritize project requests Allocate resources Form project development team for each approved project p. 412 - 413
The System Development Life Cycle Conduct preliminary investigation, also called feasibility study Perform detailed analysis Next • What is the analysis phase? p. 413
The System Development Life Cycle Next • What is the preliminary investigation? • Determine exact nature of problem or improvement and whether it is worth pursuing • Findings are presented in feasibility report p. 413 - 414 Fig. 11-6
The System Development Life Cycle Next • What is detailed analysis? 1. Study how current system works 2. Determine user’s wants, needs, and requirements 3. Recommend solution Sometimes called logical design p. 415
The System Development Life Cycle Assesses feasibility of each alternative solution Recommends the most feasible solution for the project Presented to steering committee, which decides how system will be developed Next • What is the system proposal? p. 415
The System Development Life Cycle Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click Outsourcing below Chapter 11 Next • What are possible solutions? Horizontal market software—meets needs of many companies Buypackaged software—prewritten software available for purchase Vertical market software—designed for particular industry Write own custom software—software developed at user’s request Outsource—have outside source develop software p. 415
The System Development Life Cycle Next • What is the design phase? Acquire hardware and software Develop all details of new or modified information system p. 416
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The System Development Life Cycle Next • What is needed to acquire new hardware and software? • Identify all hardware and software requirements of new or modified system Identify technicalspecifications Solicit vendor proposals Test and evaluate vendor proposals Make a decision p. 416
The System Development Life Cycle Vendor quotes price(s) for listed product(s) Identifies product(s) you want Vendor selects product(s) that meet(s) your requirements and then quotes price(s) Less formal method that uses standard form to request information about product or service Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click Request for Proposals below Chapter 11 Next • What are three basic documents used to summarize technical specifications? Request for quotation (RFQ) Request for proposal (RFP) Request for information (RFI) p. 416
The System Development Life Cycle Next • What is a value-added reseller (VAR)? • Complete system provided by value-added reseller • Value-added reseller (VAR) purchases products from manufacturer and then resells them, offering additional services with product • Authorized VARs must meet certain manufacturer-specified requirements p. 417 Fig. 11-7
The System Development Life Cycle Next • How do systems analysts test software products? • References from vendor • Talk to current users of product • Product demonstrations • Trial version of software • Benchmark testmeasures performance p. 417
The System Development Life Cycle Next • What is a detailed design? Detailed design specifications for components in proposed solution Includes several activities Database design Input and output design Program design p. 418 - 419
The System Development Life Cycle Next • What is a mockup? • Sample of input or output that contains actual data p. 418 Fig. 11-8
The System Development Life Cycle Next • What is a layout chart? • Input or output that contains programming-like notations for data items p. 419 Fig. 11-9
The System Development Life Cycle Next • What is a prototype? Working model of proposed system Beginning a prototype too early may lead to problems p. 419
The System Development Life Cycle Next • What is computer-aided software engineering (CASE)? • Software tools designed to support activities of system development cycle p. 419 Fig. 11-10
The System Development Life Cycle Next • 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 p. 420
The System Development Life Cycle Next • What are the four types of tests performed by system developers? Unit Test Systems test Verifies each individual program works by itself Verifies all programs in application work together Integration Test Acceptance Test Verifies application works with other applications Verifies the new system works with actual data p. 420
The System Development Life Cycle Next • What istraining? • Showing users exactly how they will use new hardware and software in system p. 420 - 421 Fig. 11-11
The System Development Life Cycle Next • What are conversion strategies? • Used to change from old system to new system p. 421
Perform maintenance activities The System Development Life Cycle Next Monitor system performance • What is the operation,support, and security phase? • Provides ongoing assistance after system is implemented Assess system security p. 422
The System Development Life Cycle Next • What is a computer security plan? • Summarizes in writing all of the safeguards that are in place to protect a company’s information assets Identify allinformation assets of an organization Identify allsecurity risksthat may cause an informationloss For each risk,identify thesafeguards that exist to detect, prevent, and recover from a loss p. 422
Programming Languages Next • What is a computer program? • Set of instructions that directs computer to perform tasks • Programming language—used to communicate instructions p. 423 Fig. 11-12
Programming Languages Next • What are low-level languages and high-level languages? Low-levellanguage High-level language Machine-dependentruns only on one type of computer Oftenmachine-independentcan run on many different types of computers and operating systems Machine and assembly languages are low-level p. 424
Programming Languages Next • 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 p. 424 Fig. 11-13
Programming Languages Next • What is assembly language? • Instructions made up of symbolic instruction codes, meaningful abbreviations and codes • Source program contains code to be converted to machine language p. 424 - 425 Fig. 11-14
Programming Languages Next • What is a procedural language? Programmer writes instructions that tell computer what to accomplish and how to do it Uses series of English-like words to write instructions Often called third-generation language (3GL) p. 425
Programming Languages Next • What is a compiler? • Program that converts entire source program into machine language before executing it p. 425 Fig. 11-15
Programming Languages Next • What is an interpreter? • Program that translates and executes one program code statement at a time • Does not produce object program p. 426 Fig. 11-16
Programming Languages Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click COBOLbelow Chapter 11 Next • What is COBOL? • Designed for business applications • English-like statements make code easy to read, write, and maintain • COmmon Business-Oriented Language p. 426 Fig. 11-17
Programming Languages Next • What is C? • Powerful language originally designed to write system software • Requires professional programming skills p. 427 Fig. 11-18
Programming Languages Next • What is an object-oriented programming (OOP) language? Used to implement object-oriented design Major benefit is ability to reuse existing objects Event-driven—checks for and responds to set of events Java, C++, C#, and Visual Basic are complete object-oriented languages Object is item that contains data and procedures that act on data Event is action to which program responds p. 427
Programming Languages Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click JavaPlatforms below Chapter 11 Next • What is Java? • Developed by Sun Microsystems • Similar to C++ but uses just-in-time (JIT) compiler to convert source code into machine code p. 427 - 428 Fig. 11-19
Programming Languages Click to view Web Link,click Chapter 11, Click Web Linkfrom left navigation, then click C++below Chapter 11 Next • What is C++? • Includes all elements of C, plus additional features for working with object-oriented concepts • Used to develop database and Web applications • What is C#? • Object-oriented programming language based on C++ • Accepted as a standard for Web applications and XML-based Web services p. 428