Systems DevelopmentJun 09, 2005 · Rapid and inexpensive Useful when requirements are uncertain or when end-user interface is important Promotes user participation Requirements specified

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Copyright V.C. Storey, M.M. Moore 2005 1

Systems DevelopmentMBA 8125 – Week 8

Sources: Schenk Seidmann K. Schwaig McConnell Laudon and Laudon 2006


Corporate

Strategy

Ethics/Privacy

ISStrategyand Plan

InternalSystems

Development

OutsourcedSystems

Development

Implementation

InternalSystems

Operations

OutsourcedSystems

Operations

Infrastructure

Security

Course Overview

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Agenda Software Engineering Systems Development Life Cycle Alternative Methodologies

Prototyping End-user development Outsourcing

Managing Software Projects


Why Develop an Information System? Phenomena that trigger IS development

An opportunity (proactive) A problem (reactive) A directive

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System Interdependence

BusinessStrategy

Rules

Processes

Figure 1.2 (Laudon & Laudon 2006)


Management Challenges Organizational changes Fit organization’s strategic plans Systems development strategy

Traditional Alternative methodologies

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Ultimate Management Challenge“... It’s hard work to make improvements

without changing anything...”

Mikahail Gorbachev, from his address to theSupreme Soviet Congress, February, 1986


“The study of methods for producing high quality software atminimum cost.”

Stakeholders: Users, managers, designers, programmers,competitors.

Issues: Efficiency, quality, delivery target, changingrequirements, innovation, team interaction, team incentives,project organization and management, software structure,reusability, prototyping, formal description techniques,development tools.

What is Software Engineering

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Project Planning Systems Analysis Systems Design Implementation Integration and Testing Installation Maintenance

Systems Development Life CycleSystems

Analysis

Systems

Design

Program

ming

Testing

Testing

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Planning/Definition Put project in context Small part of much larger system New system or modify old

Study/Analysis User requirements Analyze task Break into sub-components

Design - Define system to be built Description

SDLC Phases


Implementation Write code

Integration and Testing Unit Testing, System Testing, Acceptance Testing

Installation Testing, training, conversion

Maintenance: Respond to needs of users Fix bugs, add facilities

SDLC Phases (continued)

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Group Activity In Groups of 3-4:

Elect a recorder and a reporter in the group For each of the activities in the SDLC, what is the

role of the IT department and the managers/usersrequesting the software

Record your discussion on a sheet of paper toturn in

We’ll discuss your answers in class


The Classic Waterfall Life Cycle Methodology

Planning/ definition

Study/analysis

Design

Programming

Installation

Maintenance

STAGES

Project proposal reportSystem proposal report

Design specificationsProgram code

Testing and installation

Postimplementation audit

END PRODUCTS

OPERATIONSMilestone 1

Project initiation

Milestone 2Designsolutiondecision

Milestone 3 Designspecification sign-off

Milestone 4 Productiondecision

Year 1 Year 2 3-8 year lifespan

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Spiral (Iterative) Model


“Make sure thesystem works!”

Importance of Testing Unit Test Integration Test Full System Test Stress Testing Field Testing (Alpha and Beta

Tests) Regression Testing

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Strategies usedto convert fromone IS toanother

Installation: Conversion Strategies


Activities in Systems Support

Maintenance and Support

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Alternative Methodologies Other options for software development:

Rapid Prototyping Iterative Development “Off the Shelf” Applications End User Development Outsourcing

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Build experimental system to demonstrate, evaluateapproach; users refine needs

Prototype: Preliminary working version of informationsystem for demonstration, evaluation purposes

Problems: Omission of basic requirements.

Lack of documentation, testing.

Prototyping tools may not be capable of developing complexsystems.

Users see prototype and expect to be able to use it.

Alternative Methodologies:Rapid Prototyping


Prototyping Guidelines

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In iterative development, refinement of the system continues until usersare satisfied.

Alternative Methodologies:Iterative Development


Alternative Methodologies:End-User Development End-users develop system with little help from

technical specialists Only appropriate for small, desktop applications Users have autonomy over system

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Alternative Methodologies:End-User Development Management Benefits

Improved requirements determination Development controlled by users Reduced application backlog

Management Problems Insufficient review / analysis Lack of standards and controls Proliferation of “private” information systems

and data


Alternative Methodology:Acquiring Software Packages Commercial Off the

Shelf (COTS)Packages Set of prewritten

application softwareprograms that arecommercially available

Modification ofsoftware package tomeet organization’sneeds may be required

Figure 14.12 – Laudon & Laudon 2006

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The purchase of anexternally produced good orservice that was previouslyproduced internally

Alternative Methodology:Outsourcing


Advantages Economy Predictability Frees up human resources

Disadvantages Loss of control Vulnerability of strategic information Dependency

Outsourcing

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Comparison of Systems Development Approaches

Can lead to proliferation ofuncontrolled informationsystemsSystems do not always meetquality assurance standards

Users control systems-buildingSaves development timeand costReduces applicationbacklog

Systems created by endusers using fourth-generation softwaretoolsRapid and informalMinimal role of IT dept

End-user Development

Inappropriate for large, complexsystemsCan gloss over steps in analysis,documentation, and testing

Rapid and inexpensiveUseful whenrequirements areuncertain or when end-user interface isimportantPromotes userparticipation

Requirements specifieddynamically withexperimental system

Rapid, informal, anditerative process

User interacts withprototype

Prototyping

Slow and expensiveDiscourages changesMassive paperwork to manage

Necessary for largecomplex systemsand projects

Sequential step-by-stepprocess

Written specificationand approvals

Limited role of users

Systems Lifecycle(Waterfall)

Approach Features Advantages Disadvantages


May not meetorganization’s uniquerequirementsMay not perform manybusiness function wellExtensive customizationraises development costs

Design, programming,installation, and maintenancework reducedCan save time and cost whendeveloping commonbusiness applicationsReduces need for internalinformation systemsresources

Commercial softwareeliminates need forinternally developedsoftware programs

Application Software Package

Loss of control over theinformation systemsfunctionDependence on thetechnical direction andprosperity of externalvendors

Can reduce or control costsCan produce systems wheninternal resources notavailable or technicallydeficient

Systems built andsometimes operated byexternal vendors

Outsourcing

Comparison of Systems Development Approaches

Approach Features Advantages Disadvantages

F0471

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Conclusions Software engineering is a challenging process Non-IS managers and personnel have a role in

software development Multiple methodologies for developing

software Difficult to manage software projects, but

there are tools to help

Documents

Systems DevelopmentJun 09, 2005 · Rapid and inexpensive Useful when requirements are uncertain or when end-user interface is important Promotes user participation Requirements specified