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IntroductionIntroduction to to Information Information TechnologyTechnology

Chapter 14:Chapter 14:

Information Systems Information Systems DevelopmentDevelopment

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Chapter PreviewChapter Preview

• In this chapter, we will study:– Planning process for IS application

development– The process of developing systems as outlined

in the SDLC– Alternatives to the SDLC and why they are

useful– Ways to obtain applications from outside the

organization– Methods that are useful in developing

Internet/intranet applications

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Information Systems Planning Information Systems Planning ProcessProcess

IS Development ProjectsIS Development Projects

Organization Mission

Organization Mission

Business AssessmentBusiness

Assessment

Organization Strategic PlanOrganization Strategic Plan

Current Information Technology Architecture

Current Information Technology Architecture

IS Strategic PlanIS Strategic Plan

New Information Technology ArchitectureNew Information Technology Architecture

IS Operational PlanIS Operational Plan

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IS Strategic PlanIS Strategic Plan• Objectives

– Align with the organization’s strategic plan– Provide for an IT architecture that enables

users, applications, and databases to be seamlessly networked and integrated

– Allocate IS development resources efficiently among competing projects, so the projects can be completed on time, within budget, and have required functionality

• Issues - efficiency; effectiveness; competitiveness

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IS Operational PlanIS Operational Plan• Mission - the mission of the IS function• IS environment - the summary of the

information needs of the functional areas and of the organization as a whole

• Objectives - the IS function’s current best estimate of its goals

• Constraints - technological, financial, and personnel limitations on the IS function

• Long-term systems need - a summary of the processes needed by a company and the IS projects selected to support them and reach organizational goals

• Short-range plan - an inventory of current projects, and a detailed plan of projects to be developed or continued during the current year

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• SDLC - the development method used by most organizations today for large, complex systems

• Systems Analysts - IS professionals who specialize in analyzing and designing information systems

• Programmers - IS professionals who modify existing computer programs or write new computer programs to satisfy user requirements

• Technical Specialists - experts in a certain type of technology, such as databases or telecommunications, who help create information systems

Information Systems Information Systems Development TermsDevelopment Terms

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The Traditional SDLCThe Traditional SDLC(1) Systems Investigation

(2) Systems Analysis

(3) Systems Design

(4) Programming

(5) Testing

(6) Implementation

(7) Operation

(8) Maintenance

Go Back to a previous Stage or Stop

An eight-stage systems development life cycle (SDLC)

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• System Investigation– Feasibility study determines the probability of success

of proposed system’s development project. Includes …• Technical feasibility (will we be able to build the system?)• Economic feasibility (how much will it cost to build the

system and how much will it benefit us?)• Behavioral feasibility (if we build the system, will it be

accepted and used?)

• Systems Analysis– Examines the business problem(s) that the

organization plans to solve with information systems– Determines what the new system must do by

examining:• Strengths and weaknesses of the existing system• Functions that the new systems must have to solve the

business problem(s)• User information requirements for the new system

Phases in SDLCPhases in SDLC

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• Systems Design– Describes how the system will fulfill the user

requirements – Develop both logical design and physical design– Output => technical design or system specification…

• system outputs, inputs, and user interfaces• hardware, software, databases, telecommunications,

personnel, and procedures• how these components are integrated

• Programming– the translation of the design specifications into

computer code– structured programming techniques improve the

logical flow of the program by decomposing the computer code into modules

Phases in SDLC Phases in SDLC (continued)(continued)

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• Testing– Checks to see if the computer code will produce the

expected and desired results under certain conditions

• Implementation– The process of converting from the old system to the

new system– Four major conversion strategies

• Parallel conversion: the old and new systems operate simultaneously for a period of time

• Direct conversion: the old system is cut off and the new systems is turned on at a certain point in time

• Pilot conversion: introduces the new system in one part of the organization

• Phased conversion: introduces components of the new system in stages

Phases in SDLC Phases in SDLC (continued)(continued)

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• Operation– the new system will operate for a

period of time, until it no longer meets its objectives

• Maintenance (simultaneous with Operation)– debugging the programs– updating the system to accommodate

changes in business conditions– adding new functionality to the system

SDLC PhasesSDLC Phases

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• Prototyping– Starts with only a general idea of user requirements,

and develops models of the system ‘until it’s right’

• Advantages:– 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

• Disadvantages:– Replaces the systematic analysis and design stages

of the SDLC - quality may be sacrificed– Can result in an excess of iterations

Alternatives to the SDLCAlternatives to the SDLC

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• Joint Application Design (JAD)– A group-based method for collecting user

requirements and creating staged designs

• Advantages:– Saves time– Greater support for, and acceptance of new systems– Produces higher quality systems– Easier implementation– Lower training costs

• Disadvantages:– Very difficult to get all users to JAD meetings– All the problems that may be caused by any group

process


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• Rapid Application Development (RAD)– A method that can combine JAD, prototyping,

and integrated CASE tools, to rapidly produce a high-quality system

• Advantages:– Active involvement of users in the development

process– Speeds the development process– Reduces development costs– Can create applications that are easier to maintain and

modify

• Disadvantages:– May result in systems with limited functionality and

adaptability for change


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• Integrated Computer-Assisted Software Engineering (ICASE) Tools– Automate many of the tasks in the SDLC

• Advantages:– Produces systems with a longer effective operational life– Speeds up the development process and result in

systems that are more flexible and adaptable to changing business conditions

– Results in excellent documentation

• Disadvantages:– More expensive to build and maintain initial system– Requires more extensive and accurate definition of user

needs and requirements– Difficult to customize and may be difficult to use with

existing systems


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• Object-Oriented Development – A fundamentally different view of computer systems

• Advantages:– Reduces the complexity of systems development and

leads to systems that are easier and quicker to build an maintain

– Improves programmers’ productivity and quality– More flexible– Allows systems analysts to think as users do about the

system– Ideal for developing Web applications– Depicts the system in user terms, increasing

understanding of what the new system does and how it meets its objectives

• Disadvantages– Runs more slowly– Need to retrain the programmers in OO methodology


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Development Outside the IS Development Outside the IS DepartmentDepartment

• End User Development– Users perform ad hoc programming to solve

business problems– 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• Backlog of IS projects• Apparent cost savings

– End-users (usually) don’t produce adequate documentation or perform adequate testing

– Security may be breached

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• External Acquisition of Prewritten Software– 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


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• Application Service Providers (ASPs)– 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


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OutsourcingUsing third parties to provide some or all

functions and services of the IT department IT may not be a core competency of the firm;

better to hire outside specialistsAdvantages:

Outsourcer can obtain hardware capabilities less expensively due to economies of scale

Outsourcer can hire needed technical staff Outsourcer specializes in providing computer

services Ability to expense outsourcing fees provides

tax benefits

Development Outside the IS Department

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Outsourcing (continued)Disadvantages:

Economies of scale may be of limited valueStaffing depends on outsourcers needs, not

client’sLack of familiarity with business/industryContract problems Internal cost reduction opportunities could

eliminate the advantage of outsourcersGuidelines:

Write short-period contracts or have flexibility since business needs are dynamic

Use of subcontractors should be controlledUse selective outsourcing only for those

functions where it makes sense

Development Outside the IS Department

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Building Internet & Intranet Building Internet & Intranet ApplicationsApplications

• Much future development will likely be Web pages due to their simplicity and ease of development

• SDLC probably not followed due to simplified Web development

• A Strategy for Internet/Intranet Development

– Identify the objectives for organizational Web site(s) and pages

– Include infrastructure requirements as well as security and legal issues in plans

– Obtain/assign necessary personnel and provide oversight

– Identify and prioritize potential projects

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Building Internet & Intranet Building Internet & Intranet ApplicationsApplications

• JAVA - A Promising Tool– Important programming language for

putting extra features into Web pages– An object-oriented language designed

for implementation on networks– Includes numerous security features

to prevent downloaded programs from damaging files or creating other problems on the receiving computer

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SummarySummary• IS Strategic and Operational Plans derive from

the organization’s strategic plan and current IT architecture

• The SDLC provides a basic framework for the process of development information system applications

• There are several alternatives to the SDLC, including prototyping and RAD

• IS applications can also be obtained outside the IS organization, including end user development, package purchases, ASPs, and outsourcing

• Development for Internet/intranet applications generally follows prototyping process

camunit 3

Documents

building internet

operational

computer code

systems analysts

business problem

department

systems

development