Post on 12-Jan-2016
AIS Development Strategies
Lecture 4-2 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Introduction
This lecture discusses three ways to obtain a new information system: purchasing prewritten software, developing software in house, and hiring an outside company (outsourcing).
It also presents ways of speeding up or improving the development process.
Lecture 4-3 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Systems Implementation
Conversion: There are four conversion
approaches.1. Direct conversion
2. Parallel conversion
3. Phase-in conversion
4. Pilot conversion
Lecture 4-4 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Systems Implementation
Old system
New system
Direct Conversion Method
Lecture 4-5 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Systems Implementation
Old system New system
Parallel Conversion Method
Lecture 4-6 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Systems Implementation
Phase-in Conversion Method
Old system
New system
Lecture 4-7 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Systems Implementation
Pilot Conversion Method
1 2 3 31 2
33 22 11
Old Old Old Old Old New
Old New New New New New
Lecture 4-8 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Ways to obtain an AIS
Purchase
(Pre-written
Build
(Customized)
Lease
(Pre-written)
Canned Software
Turnkey
(H/W & S/W)
In-house Developed
Out-sourced
(External)
Application Service Provider (ASP)
“Modified” Canned
Software
I.S. Developed
End-user Developed
(EUD)
Lecture 4-9 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Purchase Software
Canned software is written by computer manufacturers or software development companies.
It is sold on the open market to a broad range of users with similar requirements.
Turnkey systems are a combination of software and hardware sold as a package.
Lecture 4-10
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Purchasing Software and The SDLC Companies that buy rather than
develop AIS software still go through the systems development life cycle (SDLC).
1. Systems analysis2. Conceptual design3. Physical design4. Implementation and conversion5. Operation and maintenance
The Systems Acquisition Process
Will packagemeet needs?
Developsoftwareinternally
Send RFP forhardware,
if necessary
Evaluateproposal
No
Yes
Investigatesoftwarepackages
Can packagebe modified?
Send RFP forsoftware and
hardware
No
Yes
Select bestcombination
Lecture 4-12
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Development by In-House IS Department In the past, most organizations had
their information system departments develop custom software, because canned software that fit their specific needs was not available.
Developing custom software is difficult and error-prone.
It also consumes a great deal of time and resources.
Lecture 4-13
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Development by In-House IS Department Custom software is usually developed and
written in house. Alternatively, organizations may engage an
outside company to develop a package or assemble it from their inventory of program modules.
When contracting with an outside organization, a company should maintain control over the development process.
Lecture 4-14
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Development by In-House IS Department
What guidelines are recommended?– carefully select a developer– sign a contract– plan and monitor each step– maintain effective communication– control all costs
Lecture 4-15
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
End-User-Developed Software End-user computing (EUC) is the hands-on
development, use, and control of computer-based information systems by users.
When end users began to meet their initial information needs two things happened:1 Users realized computers could be used to
meet more and more information needs.2 Increased access to data created many new
uses and needs for information.
Lecture 4-16
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
End-User-Developed Software What are some examples of end-user
development uses?– retrieving information from company
databases to produce simple reports or to answer one-time queries
– performing “what if” sensitivity or statistical analyses
– developing applications using prewritten software (spreadsheet or database system)
End-User-Developed Software
Benefits of End-User Computing
User creation, control, and implementation Systems that meet user needs Timeliness
Freeing up IS resources Versatility and ease of use
Lecture 4-18
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
End-User-Developed Software
Risks of End-User Computing Logic and development errors
Inadequately tested applications Inefficient systems
Poorly controlled and documented systems Systems incompatibility Duplication of systems
Increased costs
Lecture 4-19
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Outsource the System
What is outsourcing?It is hiring an outside company to
handle all or part of an organization’s data processing activities.
In a mainframe outsourcing agreement, the outsourcers buy their client’s computers and hire all or most of the client’s employees.
Lecture 4-20
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Outsource the System
In a client/server or PC outsourcing agreement, an organization outsources a particular service, a segment of its business, a particular function, or PC support.
Lecture 4-21
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Outsource the SystemBenefits of Outsourcing
A business solution Asset utilization
Access to greater expertise and more advanced technology
Lower costs Improved development time
Elimination of peaks and valleys usage Facilitation of downsizing
Lecture 4-22
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Outsource the System
Risks of Outsourcing Inflexibility
Loss of control Reduced competitive advantage
Locked-in system Unfulfilled goals
Lecture 4-23
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
ASPs
An Application Service Provider (ASP) is a company that provides access to and use of application programs via the Internet.
The ASP owns and hosts the software; the contracting organization accesses the software via the Internet.
Lecture 4-24
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Factors to Consider When Evaluating ASPs
Advantages Lower costs Automatic upgrading to
current version of software
Need fewer in-house IT staff
Reduced hardware needs
Flexibility Knowledge support Security and privacy of
data
Disadvantages Viability of ASP Security and privacy of
data Availability and
reliability of service Inadequate support or
poor responsiveness to problems
Standard software that may not meet all customized needs
Lecture 4-25
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Business Processes Reengineering What is business process reengineering
(BPR)? It is the thorough analysis and complete
redesign of business process and information systems to achieve performance improvements.
It is a process that challenges traditional organizational values and cultures associated with underperformance.
Lecture 4-26
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Prototyping
What is prototyping?– an approach to systems design in
which a simplified working model of a system is developed.
A prototype, or “first draft,” is quickly and inexpensively built and provided to users for testing.
Lecture 4-27
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Prototyping
What four steps are involved in developing a prototype?1. Identify basic systems requirements.
2. Develop an initial prototype that meets the agreed-on requirements.
3. Users identify changes, developers make changes, and the system is turned over to the user.
4. Use the system approved by the users.
Lecture 4-28
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Prototyping
Advantages of Prototyping
Better definition of user needs Higher user involvement and satisfaction
Faster development time Fewer errors More opportunity for changes
Less costly
Lecture 4-29
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
End-User-Developed Software
Disadvantages of Prototyping Significant user time Less efficient use of system resources
Incomplete systems development Inadequately tested and
documented systems Negative behavioral reactions
Unending development
Lecture 4-30
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Computer-Aided Software Engineering (CASE) CASE is an integrated package of
computer-based tools that automate important aspects of the software development process.
CASE tools are used to plan, analyze, design, program, and maintain an information system.
They are also used to enhance the efforts of managers, users, and programmers in understanding information needs.
Lecture 4-31
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Computer-Aided Software Engineering (CASE) CASE tools do not replace skilled
designers; instead they provide a host of self-integrated tools that give developers effective support for all SDLC phases.
CASE software typically has tools for strategic planning, project and system management, database design, screen and report layout, and automatic code generation.
Lecture 4-32
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Computer-Aided Software Engineering (CASE)
Advantages of CASE Technology
Improved productivity Improved program quality
Cost savings Improved control procedures
Simplified documentation
Lecture 4-33
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Computer-Aided Software Engineering (CASE)
Disadvantages of CASE Technology Incompatibility
Unmet expectations
Lecture 4-34
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
End of Lecture