Chapter 5 Information Systems in Business: Software
-
Upload
georgia-steele -
Category
Documents
-
view
30 -
download
2
description
Transcript of Chapter 5 Information Systems in Business: Software
Management Information Systems, 3rd EditionEffy Oz
1
Chapter 5Information Systemsin Business: Software
Management Information Systems, 3rd EditionEffy Oz
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.
Management Information Systems, 3rd EditionEffy Oz
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.
Management Information Systems, 3rd EditionEffy Oz
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.
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
6
Programming Languages
• 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.
Management Information Systems, 3rd EditionEffy Oz
7
Programming Languages
• 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.
Management Information Systems, 3rd EditionEffy Oz
8
Programming Languages
• 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.
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
11
Programming Languages
• 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
Management Information Systems, 3rd EditionEffy Oz
12
Programming Languages
Figure 5.3 Advantages of object-oriented programming (OOP) over procedural languages
Management Information Systems, 3rd EditionEffy Oz
13
Programming Languages
Figure 5.4 The object EMPLOYEE
Management Information Systems, 3rd EditionEffy Oz
14
Programming Languages
Figure 5.5 Advantages and disadvantages of higher-level programming languages
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
18
Application Software
Figure 5.7 Advantages and disadvantages of tailored applications
Management Information Systems, 3rd EditionEffy Oz
19
Application Software
• 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
Management Information Systems, 3rd EditionEffy Oz
20
Application Software
Figure 5.8 Advantages and disadvantages of packaged software
Management Information Systems, 3rd EditionEffy Oz
21
Application Software
• Packaged Software – Word processors
– Electronic spreadsheets
– Database management systems
Management Information Systems, 3rd EditionEffy Oz
22
Application Software
• 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
Management Information Systems, 3rd EditionEffy Oz
23
Application Software
• Packaged Software – Hypermedia (Hypertext)
• First called Hypertext– The concept was limited to text
• Hypermedia enables linking of text, pictures, sounds, and animations
Management Information Systems, 3rd EditionEffy Oz
24
Application Software
• 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
Management Information Systems, 3rd EditionEffy Oz
25
Application Software
• 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
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
28
System Software
Figure 5.10 The operating system mediates between applications and the computer, and controls peripheral devices.
Management Information Systems, 3rd EditionEffy Oz
29
System Software
Figure 5.11 Computers operate on a number of layers, starting from the user interface and moving inward to the hardware.
Management Information Systems, 3rd EditionEffy Oz
30
System Software– Operating System Functions
• Systems Management• User Interface• Memory Allocation• Multitasking, Multiprogramming,
and Multiprocessing• Times and Statistics• Increasing Services from O/Ss
Management Information Systems, 3rd EditionEffy Oz
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
Management Information Systems, 3rd EditionEffy Oz
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.