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1111 SYSTEMS SYSTEMS

DEVELOPMENT DEVELOPMENT

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Information Systems Plan

Road map indicating direction of system development:

• Goals/Rationale• Current situation• New developments• Management decisions• Implementation plan• Budget

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Enterprise Analysis

Business system planning (BSP): Helps identify key entities & attributes in organization’s data

Analysis of organization-wide information needs in terms of:– Organizational units

– Functions

– Processes

– Data elements

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Strategic Analysis

Critical Success Factors (CSF)• A small number of easily identifiable

operational goals• Shaped by industry, manager, environment• Believed to assure firm’s success• Used to determine organization’s

information requirements

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IS Problem Areas

Design– User interface– Doesn’t do what intended to do

Data– Data accuracy & consistency

Cost– Too expensive to run– Too expensive to complete

Operations– System does not run well

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Model of Organizational Change

• Unfreezing– Prepare those affected by change

– Communicate reasons

– Solicit feedback

• Moving– Training of those affected by change

• Refreezing– Routinization of the change

– Becomes “second nature”

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Causes of Implementation Success & Failure

• The role of users in the implementation process

• The degree of management support

• Level of complexity and risk

• Quality of management of the implementation process

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Level of Complexity & Risk

• Project Size– Larger projects higher risk

– Large = cost, size of staff, time to implement

• Project Structure– Lower structure higher risk

– Structure = requirements inputs and outputs known

• Experience with technology– Lower experience higher risk

– Experience of project team and info systems staff

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Systems Development

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Systems Analysis

Analysis of problem to be solved with an information system

• Feasibility study: Can problem be solved within constraints?– Financial - Legal – Technical - Organizational

• Establish Information Requirements– Identifies who needs what information, and when,

where and how it is needed

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Systems Design

• User Interface• Database Design• Processing• Security• Conversion• Training• Organizational change

Details how a system will meet the information requirements

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Completing Systems Development

• Programming– Translate system specifications into program code

• Testing– Unit testing (test each program)

– System testing (tests info system as a whole)

– Acceptance testing (final testing, evaluated by users)

– Test plan

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Conversion

• Parallel approach– Old and new systems used together until assured that new system

functions correctly

• Direct cutover– New system completely replaces old one on an appointed day

• Pilot study– New system introduced to a limited area of the organization

• Phased approach– New system introduced in stages by function

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Production and Maintenance

• Operate the system

• Evaluate the system

• Modify the system and relevant documentation

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Systems Development Life Cycle (SDLC)

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SDLC Limitations

Strengths Weaknesses

Good for large, complex systems Slow and expensive

Discourages changes

Massive paperwork to manage

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Prototyping

1. Identify basic user’s requirements

2. Develop an initial prototype

3. Use prototype

4. Revise & enhance prototype

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Prototyping

Strengths Weaknesses

Rapid and relatively inexpensive Inappropriate for large complex systems

Useful when requirements are uncertain or when end user interface is critical

Can gloss over steps in analysis, documentation and testing

Promotes user involvement

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Application Software Packages

Prewritten, precoded application software, commercially available for sale or lease

• Geared to common requirements

• Customization– Modification of software to meet organization’s

needs– Benefits of using packages whittled away by

excessive changes

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Software Packages

Strengths Weaknesses

Design, programming, installation and maintenance work reduced

May not meet organization’s unique requirements

Can save time and cost when developing common business applications

May not perform many business functions well

Reduces need for internal information systems resources

Extensive customization raises development costs

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End User Development

Strengths WeaknessesImproved requirements determination Relatively inefficient; Slow

transaction processing

Increased user involvement & satisfaction

Testing and documentation may be inadequate

May carry high cost: end users away from normal duties

End users develop systems,using fourth generation tools, with little assistance from technical experts,

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Outsourcing

Contracting applications development, or computing centre operations, to external vendors

Strengths WeaknessesCan reduce or control costs Loss of control over systems

development process

Can produce systems when internal resources are not available

Dependence on the technical direction and prosperity of external vendors

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Other methodologies

• Object-oriented development– Combines data and procedures to create objects– reusability

• Unified Modelling Language (UML)– Notation for logical representations of objects

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Other methodologies

• Rapid Application Development (RAD)– Develops system in a short timeframe– Uses prototyping, fourth-generation tools and

teamwork

• Joint Application Design (JAD)– Process to accelerate the generation of user

requirements– End users + information system specialists

work in intensive, interactive design sessions