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8/3/2019 Is Development PART II
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InFocus Confidential 1
Info SysInfo SysInfo Sys
DevelopmentDevelopmentDevelopment
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Agenda
Alternate development methods Prototyping
RAD
Object Oriented
External Acquisitions
Outsourcing
End user development
Project Management
CASE
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Alternative DevelopmentAlternative Development
MethodsMethods -- PrototypingPrototyping
Prototyping
A systems development method that
uses a trial-and-error approach fordiscovering how a system should
operate. Steps include:
Collecting requirements
Develop/Refine Prototype Review Prototype with Users
(Repeat the previous steps until
correct design is created)
Implement and Use System
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When to prototype and whenWhen to prototype and when
not to prototypenot to prototype
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Alternative DevelopmentAlternative Development
MethodsMethods RADRADRapid Application Development (RAD)
A rapid four-step iterative systems development method utilizing:prototyping, computer-based development tools, special managementpractices, and close user involvement
RAD Phases
The following phases areiterated until therequirements and designare completed andapproved
Requirements Planning
User Design
Construction
Move to the New System
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Alternative DevelopmentAlternative Development
MethodsMethods ObjectObject--OrientedOriented
Object-Oriented Analysis and Design (OOAD)
Similarto SDLC approaches except that it relies on the tight
coupling between data and methods and between the conceptualdesign of a system and its actual implementation.
OOAD Characteristics
The role ofanalyst and programmerare combined whilethinking about data and the operations to define the relevant
objects
The design and implementation of these objects happenquickly and simultaneously
It uses a more integrative prototyping process than the SDLC
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Alternative DevelopmentAlternative Development
MethodsMethods A ComparisonA Comparison
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Limitations to Internal SystemsLimitations to Internal Systems
BuildingBuilding
Limited ISStaff
Limited ISSkill Sets
IS Staff isOverworked
Problem IS
Performance
The IS organization does not have thecapability to build the system itself
The IS organization does not have personnelwith the correct skill sets to build the system
Current IS organization staff demands andpriorities make it impossible to build a system
The IS organization does not have the
appropriate performance level to build a system
Many times it is not feasible to consider building an informationsystem internally. Below are four situations that discourage theidea of developing a system internally
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Alternatives to InternalAlternatives to Internal
DevelopmentDevelopment
Outsourcing
Turning over some or all responsibility for an
organizations information systems development and
operations to an outside firm
External Acquisition
The purchasing of an existing system (hardware,
software, databases, network) from an outside
vendorsuch as IBM, EDS, orAccenture
End-user Development
Capitalizing on the sophistication of current users, this
technique allows the system users to develop their
system functions using a variety oftools
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External AcquisitionExternal Acquisition Steps toSteps to
ProceedProceedSteps in External Acquisition System identification, selection, and planning (same as
internal method)
Systems analysis (same as internal method)
Development of a request for proposal (RFP) a report that isused to tell vendors what the requirements are and how theymight be able to meet those requirements (hardware andsoftware)
Proposal evaluation may include viewing systemdemonstrations, evaluating the performance of those systems,
and examining criteria important to the organization and judginghow the proposed systems respond to those criteria
Vendor selection using a scoring system devised to evaluatethe competing proposal and then selecting the proposal that bestfits the organizations needs
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External AcquisitionExternal Acquisition The RFPThe RFP
(Request for Proposal)(Request for Proposal)
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External AcquisitionExternal Acquisition -- ProposalProposal
Evaluation CriteriaEvaluation Criteria
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OutsourcingOutsourcing Why Consider?Why Consider?
A firm might outsource some (or all) of its information system service for
many reasons:
Cost and quality concerns current cost and quality of information
systems is unacceptable
Problems in IS performance IS is having trouble meeting
acceptable service standards
Supplier pressures aggressive sales tactics
Simplifying, downsizing, and reengineering having a need to
focus on core processes
Financial factors turning over IS systems can strengthen a
balance sheet
Organizational culture political or organizational problems that are
difficult for IS to overcome
Internal Irritants tension between the IS staff and users
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EndEnd--User DevelopmentUser Development ToolsTools
ToolsMany tools can be used by end-users for business applicationsincluding some of the following:
Personal Computer Tools tools common to PCs (e.g.
speadsheets) that allow the creation of macros or automatedroutines by users
Query languages/report generators tools that utilize SQL toextract information from databases and generate reports in user-specified formats
Graphics generators tools that can extract relevant information
from databases and create graphs, charts, etc. Decision Support and Modeling Tools tools that support
complex decision making utilizing multidimensional models
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EndEnd--User DevelopmentUser Development
BenefitsBenefitsEnd-User Development BenefitsEmbracing end user development can help address somecommon issues with IS development including:
Cost of labor IS managers can substitute hardwareand the systems for users to develop systems for ISstaff
Long development time allowing users to develop,shortens development lead times
Slow modification users can react to their ownneeds
Work overload leveraging the talent of the end userstaff, in effect, increases the size of the IS staff
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EndEnd--User DevelopmentUser Development
PitfallsPitfalls
Pitfalls
End-user development is not a panacea, common issuesarises as it use become for prevalent including:
Lack of Standards if users do not adopt standards usedby IS professionals (documentation, error checking, testingprocedures), the IS staffcan experience problems whensupportingusers, or troubleshootingdata integrity andsecurity problems when enterprise systems are involved
Lack of continuity as users leave the organization ordepartment, new employees may not understand existingprograms and lose productivity learning or developing newapplications orreinventing the wheel
Appropriate Use of Time there is debate whether it isappropriate forskilled users and managers to be spendingtime on systems development
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Project ManagementProject Management
Dimensions of project management
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Project ManagementProject Management
Project Management Tools
Project Evaluation and Review Technique (PERT)
PERT chart shows events, required activities, and
relationships Advantage: Communication of interdependencies among
activities
Gantt Chart
Represents activities and start and completion times, but
not the relationships among activities
Advantage: Simple and linear
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Sample ImplementationSample Implementation
Process PlanProcess Plan
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CASECASE
Computer-aided Software Engineering (CASE)
These are automated software tools used by systemsdevelopers to design and implement informationsystems. These tools continue to evolve and come inmany types
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High Level Sys Design from aHigh Level Sys Design from a
CASE toolCASE tool
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Influence of CASEInfluence of CASE
Influence of CASE Tools on IndividualsCASE can dramatically increase the speed and quality ofsystem development and maintenance while having astrong impact on culture. ForIS managers it is commonlypositive due to higher quality and lower risk, while forIS
developers it is often negative for fear of replacement