Chapter 5 Information Systems in Business: Software

Management Information Systems, 3rd EditionEffy Oz

1

Chapter 5Information Systemsin Business: Software


2

Learning Objectives

• When you finish this chapter, you will:– Understand why managers must keep abreast of

software developments.– Recognize the different generations of

programming languages and how they differ.– Understand the difference between application

software and system software.


3

Learning Objectives

– Know the strengths and weaknesses of tailored software vs. off-the-shelf software.

– Be able to cite the latest major developments in application and system software.

– Recognize characteristics that are important in evaluating packaged software application for business use.


4

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.


5

Programming Languages

• 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


6


• 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.


7


• 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.


8


• Procedural Languages– Third-generation (procedural) languages are more

English-like than assembly languages.– Include FORTRAN, COBOL, BASIC– Programmers focus on the procedure of the application

problem at hand.– Some languages are standardized or portable.– Relatively easy to learn, write, and debug.


9

Programming Languages• 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.

– Include PowerBuilder, FOCUS, NOMAD, and RAMIS


10

Programming Languages• 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


11


• 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


12


Figure 5.3 Advantages of object-oriented programming (OOP) over procedural languages


13


Figure 5.4 The object EMPLOYEE


14


Figure 5.5 Advantages and disadvantages of higher-level programming languages


15

Language Translation

• Compilers and Interpreters– Compiler

• Scans source code and translates into object code• Generates error message and does not compile when

an error is found• Allows users to save programs in object code

– Interpreter• Checks one statement at a time• Changes error-free statements into ML• Generates an error message for errors


16

Application Software• Application

– A program developed to address a specific business need; software for development of such programs.

• Application-specific software – Programs designed to perform specific jobs

• General-purpose application software– Usable for different purposes


17

Application Software• Custom-Designed or Tailored Software

– Advantages:• Meeting the organization’s needs exactly• In-house developers are sensitive to the

organizational culture• Integration of special security measures• Customized software maintenance

– Disadvantages:• High cost• Production schedule subject to long delays• Incompatible with other organizations’ systems


18

Application Software

Figure 5.7 Advantages and disadvantages of tailored applications


19


• Packaged Software– Advantages include:

• Low cost

• High quality

• Vendor support

• Immediate availability

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

• Web browser is a popular ready-made application


20


Figure 5.8 Advantages and disadvantages of packaged software


21


• Packaged Software – Word processors

– Electronic spreadsheets

– Database management systems


22


• Packaged Software – Web Browsers

• Necessary for accessing Web sites

• Main purpose is to view documents written in HTML, XML, Java, ActiveX, etc.

– Web Page Authoring Tools• Make Web composition easier and faster

– Suites and OLE• Integrated software


23


• Packaged Software – Hypermedia (Hypertext)

• First called Hypertext– The concept was limited to text

• Hypermedia enables linking of text, pictures, sounds, and animations


24


• 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


25


• 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


26

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 as many applications as possible– Applications will work with system software

ONLY if they are developed to be compatible


27

System Software

• Operating Systems (O/S)– Single most important program and most

important type of 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


28

System Software

Figure 5.10 The operating system mediates between applications and the computer, and controls peripheral devices.


29

System Software

Figure 5.11 Computers operate on a number of layers, starting from the user interface and moving inward to the hardware.


30

System Software– Operating System Functions

• Systems Management• User Interface• Memory Allocation• Multitasking, Multiprogramming,

and Multiprocessing• Times and Statistics• Increasing Services from O/Ss


31

System Software• 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


32

System Software• Proprietary vs. Open Source

– Proprietary O/S: limited to using applications compatible with it

– Open O/S: compatible with virtually all applications.

• Completely open O/S does not exist

– Some O/Ss (e.g., Unix) are said to be nonproprietary, but it is still impossible to run many applications on different versions of such O/Ss.


33

Considerations in Purchasing Software

Figure 5.14 Sample results of software evaluation (5 is the highest score.)

Date post:	31-Dec-2015
Category:	Documents
Upload:	georgia-steele
View:	27 times
Download:	2 times

Chapter 5 Information Systems in Business: Software

Documents