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


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


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


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


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


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


Programming Languages (Cont.)


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


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


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


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


Fourth Generation Languages (Cont.)


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


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


Object-Oriented Programming (OOP) (Cont.)


The object EMPLOYEE


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



– Levels of Programming Languages: Pluses and Minuses

– Language Translation: Compilers and Interpreters

• Source code

• Object code

• Compiler

• Interpreter






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


Application Software

• Application-specific programs

– Programs designed to perform specific jobs

• General-purpose programs

– Usable for different purposes


Custom-Designed Application Advantages

• Meeting the organization’s needs exactly

• In-house developers are sensitive to the organizational culture


Custom-Designed Application Disadvantages

• High cost

• Production schedule subject to long delays

• Incompatible with other organizations’ systems


Advantages and Disadvantages


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


Packages Software (Cont.)


Packaged Software (Cont.)

• Word processors

• Electronic spreadsheets

• Database management systems


Packaged Software (Cont.)


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


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


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


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


Operating Systems (O/S) (Cont.)


System Software


Operating System Functions

• Systems Management

• User Interface

• Memory Allocation

• Multitasking, Multiprogramming, and Multiprocessing

• Times and Statistics

• Increasing Services from O/Ss


Popular Operating Systems


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


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


Considerations in Purchasing Software


Considerations in Purchasing Software (Cont.)


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

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

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