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Systems Development Lifecycle (SDLC)
Jason C. H. Chen (陳周宏 ), Ph.D.Visiting Professor
National Taipei University of TechnologyProfessor of MIS
Graduate School of Business AdministrationGonzaga University
Spokane, WA 99258 [email protected]
2
What Are Systems Development Activities?
1. Systems definition/investigation Management’s statement of objective and goals for
new system
2. Requirements analysis Identify features and functions
3. Component design (hardware, software, network) Based on approved user requirements
4. Implementation Purchase, build, test, and convert to new system
5. System maintenance (fix or enhance) Repair, add new features, maintain
Analysis
What Are Systems Development Activities?
BPM Provides Requirements for Systems Development 3
[1]
[2]
[4]
[3a]
[3b]
[5]
(Feasibility Study)What is it and Why it is important?
4
Assess Feasibility
Dimensions of feasibility• _______________ feasibility
Approximated, “back-of-the-envelope” analysis Purpose: eliminate infeasible ideas early Consider cost of previous projects, operational and labor
costs• __________ feasibility
Ball park estimate• __________ feasibility
Is it technically likely to meet needs?• _____________ feasibility
Fit with customs, culture, charter, legal requirements of organization
___________________ feasibility Is the proposed system legally?
Cost/Economic
Schedule
Technical
Organizational
Legal and Contractual
Systems Definition/Investigation (Feasibility Study)
OperationalFeasibility
ScheduleFeasibility
EconomicFeasibility
TechnicalFeasibility
Can we afford it? Will it be accepted?
Does the ITcapability exist?
Will it be completed bythe deadline?
Legal and Contractual Feasibility
Is the proposed system legally?
Organizational Feasibility(Is it a good fit –
objective of the organization5
What are new from the last slide?
6
Form a Project Team• Typical three personnel on a development team are:
Manager (or mangers for larger projects) Specialist:
System analysts Programmers Software testers or, other functional specialist such as accounting,
finance, and marketing
Users: Users must be involved in most of SDLC phases
• Depending on nature of project, team may also include hardware and communications specialists, database designers and administrators, and other IT specialists.
Systems Development
• What happen (and Why) to a project in the Department of Interior of Taiwan?
Phase Four: Implementation
8Fig 10-18: SDLC: Implementation Phase
Focuses on implementing the system and includes the tasks of building each of the
five system components
testing the system
and converting users to
the new system.
9
System Conversion Approaches
1. Pilot Implement entire system in limited portion of
business MRV uses system for selected customers. Advantage: limits exposure to business if system fails
2. Phased System is installed in phases or modules. Each piece is installed and tested.
3. Parallel Complete new and old systems run simultaneously Very safe, but expensive
4. Plunge (or direct) High risk if new system fails, no old system to fall
back on Only used if new system is not vital to company
operation
Installation Conversion Methods: 4 Ps
Old SystemOld System New SystemNew System
Old SystemOld System
New SystemNew System
Old SystemOld System New System
Old SystemOld System New System
Parallel
Pilot
Phased
Plunge/Direct
Cut-over time
10
Causes of Information Systems Failures
•35+ years of research on causes of information systems failures
1. Lack of user __________
2. Unclear, incomplete, and inconsistent ___________
3. Changing requirements and specifications
•Many businesses __________ research findings
involvement.
requirements.
ignore
Systems Development Lifecycle (SDLC)
