Jess Rolfe
DLA 112
chapter summaries - from chapter 10
chapter 10
building information systems
systems development life cycle
systems failure causes
• Missed deadlines
• Users’ needs not addressed
• Poor support from top management
system development methods
• can prevent failure
Designing a successful information system requires integration of
• people
• software
• hardware
SDLC
• range of clearly defined phases executed in order
• serves as framework for development of cycle or project
• waterfall model
system development life cycle
1. planning
2. requirements gathering and analysis
3. design
4. implementing
5. maintenance
phase 1
1. Planning
• Most important phase
• Designer must understand and define organisation’s problem
• Information on problem obtained by :
- Forming a task force
- Feasibility studies
Thought process during planning
1. Identify potential systems in organisation
2. Perform preliminary analysis of needs and define problem
3. Perform feasibility studies
4. Decide to proceed with model or not
1
,planning - needs analysis
Analysts must access current & future needs for organisation
Must answer following :
1. Why is the system being developed?
2. Who are the current and future users of the system?
3. Is the system new , upgrading or extension of current system?
4. Which functional areas (departments) are going to use the system?
info to be considered by analyst :
planning - task force
should have representatives from different departments
• IT department
• Systems analysts
• Technical advisors
• Top management
Joint program design
• Collective activity existing of task force members
• Structured workshop where everyone comes together to develop program
• Detailed agenda ; visual aids ; leader
• Result in final document containing definitions of planned system
Users
• Internal → employees who will use system regularly
• External → non-employees who will use the system
planning - user feedback
User should understand the 4 W’s :
WHY
• Why is the system being designed
WHO
• Who is going to use the system
WHEN
• When will the system be operational
WHAT
• What kind of capabilities will the system provide
2
, planning - FEASIBILITY STUDIES
Analysis of the proposed solutions feasibility and determine how to present solution to
management
feasibility studies are
• measured against how advantageous and practical system will be for organisation
Measured continuously through
- SDLC proses
5 dimensions of feasibility studies
• Economy
• Technical
• Operational
• Scheduling
• Legislative / legal
Economic feasibility
• Access system cost & advantages
Advantage > cost … economic feasible
• Gross profit generated by system = R500
• Cost incurred iro system = R300
• Gross profit generated by system = R100
• Cost incurred iro system = R700
Technical feasibility
• Technology used in the system
Task force must determine
1. Is technology available?
2. Is technology feasible to implement?
Operational feasibility
• Access how the proposed solution will work for the organisation
Measure how
- internal & external users would react to system
Access whether
- it is worth it to implement the system
- (the juice should be worth the squeeze)
Scheduling feasibility
• Determine if system will be finished on time
If system will not be finished on time & clients will be lost as a result thereof
- system is not feasible
3
DLA 112
chapter summaries - from chapter 10
chapter 10
building information systems
systems development life cycle
systems failure causes
• Missed deadlines
• Users’ needs not addressed
• Poor support from top management
system development methods
• can prevent failure
Designing a successful information system requires integration of
• people
• software
• hardware
SDLC
• range of clearly defined phases executed in order
• serves as framework for development of cycle or project
• waterfall model
system development life cycle
1. planning
2. requirements gathering and analysis
3. design
4. implementing
5. maintenance
phase 1
1. Planning
• Most important phase
• Designer must understand and define organisation’s problem
• Information on problem obtained by :
- Forming a task force
- Feasibility studies
Thought process during planning
1. Identify potential systems in organisation
2. Perform preliminary analysis of needs and define problem
3. Perform feasibility studies
4. Decide to proceed with model or not
1
,planning - needs analysis
Analysts must access current & future needs for organisation
Must answer following :
1. Why is the system being developed?
2. Who are the current and future users of the system?
3. Is the system new , upgrading or extension of current system?
4. Which functional areas (departments) are going to use the system?
info to be considered by analyst :
planning - task force
should have representatives from different departments
• IT department
• Systems analysts
• Technical advisors
• Top management
Joint program design
• Collective activity existing of task force members
• Structured workshop where everyone comes together to develop program
• Detailed agenda ; visual aids ; leader
• Result in final document containing definitions of planned system
Users
• Internal → employees who will use system regularly
• External → non-employees who will use the system
planning - user feedback
User should understand the 4 W’s :
WHY
• Why is the system being designed
WHO
• Who is going to use the system
WHEN
• When will the system be operational
WHAT
• What kind of capabilities will the system provide
2
, planning - FEASIBILITY STUDIES
Analysis of the proposed solutions feasibility and determine how to present solution to
management
feasibility studies are
• measured against how advantageous and practical system will be for organisation
Measured continuously through
- SDLC proses
5 dimensions of feasibility studies
• Economy
• Technical
• Operational
• Scheduling
• Legislative / legal
Economic feasibility
• Access system cost & advantages
Advantage > cost … economic feasible
• Gross profit generated by system = R500
• Cost incurred iro system = R300
• Gross profit generated by system = R100
• Cost incurred iro system = R700
Technical feasibility
• Technology used in the system
Task force must determine
1. Is technology available?
2. Is technology feasible to implement?
Operational feasibility
• Access how the proposed solution will work for the organisation
Measure how
- internal & external users would react to system
Access whether
- it is worth it to implement the system
- (the juice should be worth the squeeze)
Scheduling feasibility
• Determine if system will be finished on time
If system will not be finished on time & clients will be lost as a result thereof
- system is not feasible
3
