This document discusses different software development life cycle (SDLC) models. It describes the waterfall model as the first introduced process model where each phase must be completed before the next begins. The spiral model is presented as a combination of waterfall and risk analysis, with iterative cycles to reduce risk. The iterative enhancement model implements parts of software in cycles to identify further requirements through review.

1. Software
development Life
cycle
BCA 5th
Semester
DEEPAK SHARMA
12KSSB6031

2. CONTENTS
1. Software Development Life Cycle Models[SDLC]
2. Types of SDLC Models
3.Waterfall Model
4. Iterative Model
5. Spiral Model

3. Software Development Life Cycle
Definition:
A framework that describes the activities performed at each
stage of a software development project.
TYPES OF SDLC MODEL:
Waterfall model
Spiral model
Iterative model

4. WATER FALL MODEL
Water fall model is the first process model to be
introduced in 1970.
 It is also called as “Linear Sequential Lifecycle model”.
 In Water fall model each phase must be completed fully
before the next phase begins.
 It is classic process model, this type of models used for
small projects.

6. WATERFALL MODEL
ADVANTAGES DISADVANTAGES
Easy to understand and use Idealized, doesn’t match reality well.
Widely used and known
Difficult to integrate risk
management.
Identifies deliverables and
milestones
Costly for small teams and projects
Works well on mature products and
weak teams.
Backing up to address mistakes is
difficult.
Good for management control Delays discovery of serious errors

7. SPIRAL MODEL
 The spiral model is the combination of classic water fall model
and risk analysis.
 It is iterative, every iteration reduces risk at that particular stage
of project.
 In 1970 water fall model has been adopted as a general standard
by many GOVT.
 But there are many difficulties in that model.
 In 1988 spiral model introduced by “BOEHM”.

8. SPIRAL MODEL

9. SPIRAL MODEL
ADVANTAGES DISADVANTAGES
High amount of risk analysis. Can be a costly model to use.
Good for large and mission-critical
projects.
Risk analysis requires highly
specific expertise.
Software is produced early in the
software life cycle.
Doesn’t work well for smaller
projects
The design does not have to be
perfect
Spiral may continue indefinitely

10. ITERATIVE ENHANCEMENT
MODEL
• An iterative model does not attempt to start with a full specification
of requirements .
• The development start by specifying and implementing just part of
software.
• Which can then be reviewed in order to identify further
requirements.
• This process is then repeated , producing a new version of software
for each cycle of model

11. ITERATIVE ENHANCEMENT
MODEL

12. ITERATIVE
ENHANCEMENT MODEL
ADVANTAGES
 Requirements of complete
system are clearly defined
and understand.
 Used in big projects.
 Major requirements must be
defined.
DISADVANTAGES
 Each phase of an iteration is
rigid with no overlap.
 Costly system architecture.