AIS Development Strategies. Lecture 4-2 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart Introduction This.

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.


Systems Implementation

Conversion: There are four conversion

approaches.1. Direct conversion

2. Parallel conversion

3. Phase-in conversion

4. Pilot conversion



Old system

New system

Direct Conversion Method



Old system New system

Parallel Conversion Method



Phase-in Conversion Method

Old system

New system



Pilot Conversion Method

1 2 3 31 2

33 22 11

Old Old Old Old Old New

Old New New New New New


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)


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


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


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


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


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


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



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


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



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


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



Risks of Outsourcing Inflexibility

Loss of control Reduced competitive advantage

Locked-in system Unfulfilled goals

Lecture 4-23


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


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


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


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


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


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



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


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


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


Computer-Aided Software Engineering (CASE)

Advantages of CASE Technology

Improved productivity Improved program quality

Cost savings Improved control procedures

Simplified documentation

Lecture 4-33


Computer-Aided Software Engineering (CASE)

Disadvantages of CASE Technology Incompatibility

Unmet expectations

Lecture 4-34


End of Lecture

AIS Development Strategies. Lecture 4-2 ©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart Introduction This.

Documents

software development

ais software

combination of software

departmentcustom software

development process

information needs

new information system

handson development