1 chapter 15 systems development. 2 why develop an is? three phenomena that trigger is development...
TRANSCRIPT
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Chapter 15
Systems Development
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Why Develop an IS?Why Develop an IS?
Three phenomena that trigger IS development
– An opportunity (proactive)– A problem (reactive)– A directive
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The Systems Development Life Cycle (SDLC)
The systems development life cycle
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Analysis– Determines what need the system will
satisfy
– Investigation• Developers interview managers and
perspective users to determine business needs.
• Three feasibility studies
performed.
The Systems Development Life Cycle (SDLC)
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• The Technical Feasibility Study
• Ensures hardware and software exist to build the system
• The Economic Feasibility Study
• Benefits of the system weighed against the cost
• The Operational Feasibility Study
• Determines if system will be used as intended
The Systems Development Life Cycle (SDLC)
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DesignLogical Design
• Translation of user requirements into detailed functions of the system
Physical Design
Construction
Systems Testing
The Systems Development Life Cycle (SDLC)
Phases in systems design
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Implementation– Training– Conversion
•Parallel Conversion
•Phased Conversion
•Cold Turkey
Conversion
•Pilot Conversion
The Systems Development Life Cycle (SDLC)
8 Activities in systems support
Support
The Systems Development Life Cycle (SDLC)
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PrototypingSystems developed using an
Iterative Process
– Purpose is to develop a working model as quickly as possible, which can be tweaked and revised
– Significantly shortens systems development backlog
– Can increase risk of incompatibility and other unforeseen mishaps
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In prototyping, refinement of the system continues until users are satisfied.
Prototyping
When to prototype and when not to prototype
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Project ManagementProject Management Goals
– Complete the project on time.– Complete the project within budget.– Meet requirements.– Meet expectations.
Dimensions of project managementIS development projects: challenges and failures
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Project Management Functions–Communication Management
–Schedule Management
–Quality Management
–Financial Management
–Resource Management
Project Management
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Systems DevelopmentLed by End UsersJAD: An example of User-led
Systems Development
– Joint Application Development (JAD): method to be used in SDLU
– Uses six-step process to take the team through planning and design
The six steps of JAD
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– JAD Critical Success Factors
• All participants must be committed to JAD process.
• Customers and IS people must agree on project’s scope.
• Sponsor must be supportive and involved.
• Team members must be empowered decision makers.
• Business objectives must be clearly defined.
• Business process must be understood.
• Team members must be able to meet two or more days per week.
• Members must be committed to the team.
Systems DevelopmentLed by End Users
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Chapter-16
Alternative Avenues for Systems Acquisitions
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Outsourcing– Short-term contractual
relationship with a service firm to develop a specific application
– Long-term contractual relationship with a service firm to take over all or some of an organization’s IS functions
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Advantages of Outsourcing
– Improved financial planning– Reduced license and maintenance fees– Increased attention to core business– Shorter implementation cycles– Reduction of personal and fixed costs– Increased access to highly qualified know-
how?– Increased security
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Outsourcing
Risks of Outsourcing
–Loss of control
–Loss of experienced employees
–Risks of losing a competitive advantage
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Risks of outsourcing are higher at higher levels of management.
IT 3133
Outsourcing
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The InformationSystems Subsidiary
IS service companies that are owned by and served by one large company
Some grow large enough to service the market at large
Some corporations purchase an IS consulting firm
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Purchased Applications
Why Purchase?
–Immediate system availability
–High quality
–Low price
–Available support
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Purchased Applications
Purchasing Risks– Loose fit between needs and features
– Bankruptcy of the vendor
– High turnover of vendor personnel
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Renting Software
On-site Renting
– Client purchases a license to use a certain application for a specified time
Renting Through the Web
– Application installed at vendor’s location; client accesses through the Web or leased line
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Renting Software
Benefits and risks of software rental through the Web
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User Application Development
Factors Encouraging User Application Development
– The widespread use of PCs
– The emergence of 4GLs
– Increasing popularity of prototyping
– Increasing popularity of client/server architecture
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User Application Development
Advantages of user application development
– Shortened lead times
– Good fit to needs
– Free IS staff time
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Risks of user application development
– Poorly developed applications
– Duplication
– Security problems
– Poor documentation
User Application Development