1. Waterfall Model

2. Waterfall Model
SDLC approach
Became popular in 1970
Phases are organised in Linear Order
Output of one phase is input for next
phase

3. Waterfall Model Phases
 Proposal Definition
 Feasibility Study
 Requirements Analysis
 System Design
 Coding & Testing
 Implementation
 System Maintenance

4. Waterfall Model
Proposal
Definition
Feasibility Study
R
equirements
Analysis
S
ystem
Design
Coding & Testing
Implementation
System
maintenance

5. Strengths of Waterfall Model
Easy to understand, easy to use
Systematic for inexperienced staff
Milestones are well understood

6. Strengths of Waterfall Model
Sets requirements stability
Good for management control
(plan, staff, monitor, control)
Works well when quality is more
important than cost or schedule

7. Limitations-Waterfall Model
Every phase is considered as a distinct
phase
All requirements must be known before
hand
Deliverables created for each phase are
considered frozen – reduces flexibility

8. Limitations-Waterfall Model
Can give a false impression of progress
Little opportunity for customer to
preview the system (until it may be too
late)

9. Limitations-Waterfall Model
 For a new system determining requirements is
a difficult job
 So freezing requirements before design is not
practical
 Might be desirable to built only a part of it
 Later enhance as and when needed

10. Limitations-Waterfall Model
Freezing requirements requires choice
of H/W
In large projects, technology changes
when the system is completed

11. Limitations-Waterfall Model
Difficulty of accommodating change
after the process is underway
One phase has to be complete before
moving onto the next phase
Integration is one big bang at the end

12. Limitations-Waterfall Model
 Inflexible partitioning of the project into
distinct stages makes it difficult to change as
per customer requirements.
 Requirements should be well-understood so
that changes are fairly limited during the
design process

13. When to use?
Requirements are very well known
Product definition is stable
Technology is understood

14. When to use?
New version of an existing product
Porting an existing product to a
new platform.

15. Thank You!!