Management Information Systems, 4 th Edition 1 Chapter 5 Information Systems in Business: Software.

Management Information Systems, 4th Edition 1

Chapter 5Information Systemsin Business: Software

Management Information Systems, 4th Edition 2

Learning Objectives

• Explain why professionals must keep abreast of software developments

• Enumerate the different generations of programming languages and explain how they differ

• Explain the difference between application software and system software

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Learning Objectives (Cont.)

• Compare the strengths and weaknesses of tailored software versus off-the shelf software

• Cite the latest major developments in application and system software

• List characteristics that are important in evaluating packaged software applications for business use

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Software: Instructions to the Computer

• A computer program is a series of instructions to a computer to execute any and all processes

• Computers only “understand” instructions consisting of electrical signals alternating between two states

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Software: Instructions to the Computer (Cont.)

• Application software enables users to complete a particular task, such as word processing

• System software enables application software to run on a computer and manages the interaction between hardware devices

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Programming Languages

• Abbreviated forms of instructions that translate into machine language

• New programming languages make programming easier for people who are not necessarily hardware experts

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Programming Languages (Cont.)

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First Generation: Machine Languages (ML)

• Only languages computers can directly interpret to carry out instructions

• ML coding: time-consuming and error-prone

• ML programmers: concerned with hardware details

• Every computer or family of computers has its own ML; each is machine-dependent

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Second Generation: Assembly Languages

• Represent a string of ‘0s’ and ‘1s’ for machine language instruction

• More English-like; codes shorter than machine languages

• Assembler translates into machine language

• Advantages of machine or assembly languages

– Programmer in control of hardware

– Programs written in low-level languages run more efficiently

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Third Generation: Procedural Languages

• Third-generation (procedural) languages are more English-like than assembly languages

• Programmers focus on the procedure of the application problem at hand

• Some languages are standardized or portable

• Relatively easy to learn, write, and debug

• FORTRAN, COBOL, BASIC

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Fourth Generation Languages (4GL)

• 4GLs are more English-like than procedural languages

• Programmer only has to select an action without having to specify the action’s formula or procedure

• Easy to learn and use; shorter application development time

• PowerBuilder, FOCUS, NOMAD, and RAMIS

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Fourth Generation Languages (Cont.)

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Visual Programming

• Languages that let programmers create field windows, scroll-down menus, click buttons, etc., by choosing from a palette

• Appropriate code written automatically

• Accelerates work

• Microsoft’s Visual Basic

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Object-Oriented Programming (OOP)

• Emphasis on the objects involved in the task, not on the procedure

• An object encapsulates a data set with the code that is used to operate on it

• Standardized programming modules can be reused

• Applications can be rapidly developed with appropriate objects from an object library

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Object-Oriented Programming (OOP) (Cont.)

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The object EMPLOYEE

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Application Software vs. System Software

• Application: – Program developed to address a specific

business need; software for development of such programs

• System: – Programs designed to carry out general routine

operations, such as loading, copying, or deleting a file

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Programming Languages (Cont.)

– Levels of Programming Languages: Pluses and Minuses

– Language Translation: Compilers and Interpreters

• Source code

• Object code

• Compiler

• Interpreter

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Programming Languages (Cont.)

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Programming Languages (Cont.)

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Bugs

• Errors in a program to be eliminated before it runs smoothly

• Occur when a certain operation cannot be carried out

• Logic errors are most difficult to spot

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Application Software

• Application-specific programs

– Programs designed to perform specific jobs

• General-purpose programs

– Usable for different purposes

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Custom-Designed Application Advantages

• Meeting the organization’s needs exactly

• In-house developers are sensitive to the organizational culture

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Custom-Designed Application Disadvantages

• High cost

• Production schedule subject to long delays

• Incompatible with other organizations’ systems

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Advantages and Disadvantages

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Packaged Software• Advantages:

– Low cost

– High quality

– Vendor support

– Immediate availability

• Often tested at user sites (alpha sites and beta sites) before the final version is released

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Packages Software (Cont.)

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Packaged Software (Cont.)

• Word processors

• Electronic spreadsheets

• Database management systems

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Packaged Software (Cont.)

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Multimedia

• Can handle many different types of data such as text, voice, and image

• Powerful means of communicating

• Uses include education, training, research, and business

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Virtual Reality (VR)

• Mimics sensory reality

• Some sophisticated VR software includes use of goggles, gloves, earphones, and a moving base

• Business use of VR is expected to grow dramatically for design and testing of new products, and for marketing

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System Software• Manages computer resources and performs

routine tasks not specific to any application

– Copying and pasting sections and files

– Printing documents

– Allocating memory

• Developed to partner with application software

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Operating Systems (O/S)

• Most important system software

– Developed for a certain microprocessor or microprocessors

– Addresses technical details such as registers and RAM addresses

– Plays the role of “traffic cop” or the “boss” of computer resources

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Operating Systems (O/S) (Cont.)

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System Software

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Operating System Functions

• Systems Management

• User Interface

• Memory Allocation

• Multitasking, Multiprogramming, and Multiprocessing

• Times and Statistics

• Increasing Services from O/Ss

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Popular Operating Systems

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Data Communication Programs

• Controls and supports data communication activities in a network

– Setting up rules that govern transmission and reception of data

– Connecting and disconnecting communication links

– Assigning priorities among terminals in a network

– Detecting and correcting transmission errors

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Linux and the Open Source Revolution

• Proprietary software: source code of the software public

• Open source software: source code can be obtained free of charge

• Contains fewer bugs because thousands of independent programmers review the code

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Considerations in Purchasing Software

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Considerations in Purchasing Software (Cont.)

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Summary

• Software developments and the impact on business

• Application software versus operating system software

• Tailored software versus off-the-shelf software• Major developments in application and system

software• Evaluation of package software