(Part II)

Additional material: Stair and Reynolds

2008-

Chapter 8 via e-reserve

System Planning and Development

Accounting System Design and Development

Traditional development life cycle Prototyping

Joint application design

Rapid application development

CASE tools

Object-oriented development

Understand the concept of

system

development methodologies

Describe the advantages and

disadvantages

of traditional system development,

prototyping, joint application design, rapid

application development, and end-user

development life cycles.

Evaluate the alternatives to in-house

system

development.

May produce excessive documentation.

Users are often unwilling or unable to

study

the specifications they approve.

Takes too long to go from the important

issues to a working system.

Users have trouble describing

requirements

for a proposed system.

Forces staff to be systematic by

going

through every step in a structured

process.

Enforces quality by

maintaining

standards.

Has lower probability of missing

important issues in collecting user

requirement.

An iterative approach to the

systems

development process.

Starts with only a general idea of user

requirements, and develops models of the

system ‘until it’s right’.

During each iteration, requirements

and

alternative solutions to the problem are

identified and analyzed.

Users are encouraged to try the

prototype

and provide feedback.

Speeds up the development approach

Gives the users the opportunity to clarify

their

information requirements

Useful in the development of decision

support systems and executive information

systems Work well for ill-defined problems Help clarify user requirements

Promote close working relationship

between

systems developers and users.

A small scale working model of the

entire

system. For example, sample report or output screen

After the first preliminary model is refined,

the second, third models are introduced until

the complete system is developed.

A group-based method for collecting user

requirements and creating staged designs.

Process for data collection and

requirements

analysis in which users, stakeholders, and IS

professionals work together to analyze

existing systems, propose possible solutions,

and define the requirements of a new or

modified system.

A group normally require one or more top-

level executives who initiate the JAD process.

Can result in an excess of iterations Time consuming

If the process lacks of documentation, this

can leads to problems after the system

becomes operational and need maintenance. Not practical with large number of users.

Easy for management to understand

Greater support for, and acceptance of

new

systems Saves time

Produces higher quality systems

Easier implementation

Lower training costs

All users jointly define and agree

upon

systems requirements. Often uses group support systems (GSS)

software to foster positive group interaction.

Often used within the system analysis

and

system design stages of the SDLC.

A systems development approach that employs

tools, techniques, and methodologies designed to

speed application development.

A method that can combine JAD, prototyping,

and

integrated CASE tools, to rapidly produce a high-

quality system.

It is an iterative approach similar to

prototyping,

which emphasizes on the speed of development.

For example, IBM has a RAD tool called

Rational

Rapid Developer, to make developing large Java

programs.

Very difficult to get all users to JAD meetings. Potential to have dysfunctional groups.

All the problems that may be caused by

any

group process.

System maybe built quickly, which may

result

in lower quality.

May result in systems with limited

functionality and adaptability for change

Reduce paper-based documentation Source code are automatically generated

Can create applications that are easier

to

maintain and modify Speeds the development process Reduces development costs

Active involvement of users in

the

development process

What is Rapid Application Development

(RAD)? How does RAD differ and/or

similar

from Prototyping?

Factors that drive the trends toward

increased

end-user computing and end-user

development◦ More powerful, inexpensive desktop hardware

◦ Increasingly diverse software capabilities

◦ Increasingly computer literate population

◦ Apparent cost savings

Any systems development project in which

the primary effort is undertaken by a

combination of business managers and users.

Users perform ad hoc programming to

solve

business problems.

Creates lower-quality systems because

an

amateur does the programming

May eventually require consulting

and

maintenance assistance from the IT

department

System may not have

adequate

documentation Poor quality control

System may not have adequate interfaces

to

existing systems.

Directly meets user requirements

Bypasses the information

systems

department and avoids delays

User controls the application and can

change

it as needed Increased user acceptance of new system

Frees up IT resources and may

reduce

application development backlog

Software obtained via subscription Software resides on ASP’s systems Software is accessed via Web or VPN Subscriber does not have to host software on

existing computer systems Updates and bug fixes are provided by the

ASP ASP can provide help-desk support

Factors to consider during make-or-buy

decision◦ On-time◦ On-budget◦ Full functionality◦ User acceptance◦ Favorable costs-to-benefits ratio◦ Low maintenance◦ Scalability◦ Integration with other systems◦ Minimal negative cross-impacts◦ Reusability

When organisations may not be able to

manage technology as well as firms that

specialise in managing IT When IT is not a core competency area

When it is cheaper to outsource

When organisations do not have skilled ITstaff that can keep technology up to date.

An alternative to developing and

installing

internal AIS is to outsource them.

Under outsourcing, a company needing

data

processing services hires an outside

organization to handle all or part its data

processing services.

The degree to which a company

outsource may range from routine

assistance with a single application

to running the entire IT department.

Technical◦ Access to new information technologies

◦ Ability to achieve

technological

improvement more easily

◦ Greater access to technical skills

not

available internally

◦ Faster application development and

placement of IT application to service

Financial◦ Avoidance of heavy capital investment

◦ Improved cash flow and

cost

accountability

◦ Improved cost benefits from economies

of

scale and from sharing computer,

housing, hardware, software and

personnel◦ Less need for expensive office space

Quality◦ Improve performance accountability

◦ Improve quality accreditation

Flexibility◦ Quick response to business demands

◦ Ability to handle IT peaks and valley

more

effectively

Management◦ Concentrate on core business activity

◦ Improve company focus

◦ Elimination of need to recruit and

retain

competent of IT staff

Irreversibility of the outsourcing decision

Possible breach of contract by the vendor

or

its inability to deliver, loss of control over IT

decisions Loss of critical IT skills

Vendor lock-in

Some costs are hidden: vendor search and

contracting, transitioning fro in-house IT to a

vendor

The company may lose control ofits information system and be exposedto possible abuse.

It could be difficult for a company to break

its

contract, resulting in inflexibility.

Over the long run, a company

may

lose sight of its information needsand how the system can provide it withcompetitive advantage.

Stair, R. and Reynolds G. (2008), Fundamentals ofInformation Systems, 3rd Edition, Thompson, USA

Benson, S. and Standing, C. (2008),

Information

Systems: A Business Approach, 3rd Edition, John

Wiley & Sons, New York

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