System Development Life Cycle

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System Development Life Cycle
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What is SDLC?
The formal process by which organizations build
systems is known as SDLC. Also referred to as
Application Development Life Cycle or Structured
Development Life Cycle
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TQM/RE
TQM-Total Quality Management Set of business
practices which improve profit and
productivity RE- Reengineering/Process
Innovation Changing fundamental
procedures reexamining/repositioning
corporate Strategies.
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TQM/RE Goals

• Improve quality of all company activities
• Reduce costs
• Improve timelines
• Other business goals

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Why systems fail?

• Lack of communication between people
• Continuing the old system
• Failure of parts of system not fitting
• Lack of management Support
• Technological Incompetence
• Changes in technology in the middle
• Lack of user involvement/training/support
• (missing JAD-Joint Application Development)

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Why systems fail?(Not following steps of SDLC)

• System does not meet users needs
• Unnecessary/insufficient hardware is acquired
• Software inadequately tested

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Six Phases of SDLC

• Preliminary Investigation
• Systems Analysis
• Systems Design
• Systems Development/Acquision
• Systems Implementation
• Systems Maintenance
• Person in charge Project LeaderSystem
  Analyst/Engineer

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1. Preliminary Investigation (feasibility study)
Determine the organizations objective Read
internal/external documents Interview
users/executives Nature and scope of
problems Propose alternative solutions leave the
system as is modify the existing
system develop a new system Describe
costs/benefits of each solution Submit a
preliminary plan with recommendation
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1. Preliminary Investigation
Benefits Tangible Cost savings Profitability/Prod
uctivity Intangible Employer satisfaction
BPR (Business Process reengineering) independent
of IT Processes are identified for
bottlenecks, removed, then IT is applied.
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2. System Analysis
Gather data documents, interviews,
questionnaires, observations, sampling Analyze
data CASE tools, DFDs, Data Dictionary, System
Flowcharts, Connectivity Diagrams, Grid Charts,
Decision Tables Write a report Written
report Approval from the Manager next phase
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3. System Design
Preliminary Design describes the functional
capabilities of the system CASE tools, PM
Software Detailed Design Output
Requirements Input Requirements Storage
Requirements Processing/Network
Requirements System Backup
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4. System Development
Substantial expenditures of money/time Acquire
software Acquire hardware Test the System Unit
Testing Integrated testing Workable system
ready to be implemented
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5. System Implementation
ObjectiveTo make system not just workable but
successful 1. Software Conversion/Data
conversion 4 Major strategies Direct
Implementation Parallel Implementation Phased
Implementation Pilot Implementation 2.
Documentation 3. Training
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4. System Maintenance
Never ending phase Adjustments/improvements syst
em monitoring Auditing- independent auditors
review Evaluation- outside system analyst Once
the system is old enough SDLC is started all
over again.