This document discusses several software process models including the linear sequential model, incremental model, RAD model, evolutionary process model, prototyping model, spiral model, and concurrent development model. The linear sequential model or waterfall model involves requirement gathering, design, coding, testing, and maintenance phases. The incremental model combines elements of the waterfall model to produce increments of the software. The RAD model aims to develop a fully functional system within 60-90 days through short development cycles. Evolutionary process models allow for changes at any time, including prototyping, spiral, and concurrent development models. The spiral model uses iterative risk analysis and the concurrent model represents development activities and their associated states.
2. DEFINATION:
It can be defined as abstract representation of
process.
SDLC =Software Development Life Cycle.
PRESCRIPTIVE PROCESS = As it follows some
specific rules.
NEEDS:
(1)With the help of software process model,
software development can be done systematically.
(2)Each team member will understand what activity
is to be done next and how it will be done.
(3)Overall brings the discipline in the development
process.
5. Also called as Waterfall model or Life Cycle
model.
REQUREMENT GATHERING: Basic requirements
of the system is gathered by communicating with
customer and developers.
DESIGN: Requirements are converted into easy to
represent able form such as data structure and
algorithm.
CODING: Design is converted into machine
readable form.
TESTING: Testing is done to find errors and to
correct errors.
MAINTANANCE: When the software is installed and
made to run and then some error occurs so
,correcting these errors is the task of this phase.
6. ADVANTAGES:
Simple to be implemented.
Good for implementation of small system.
DISADVANTAGES:
• If change in any one phase is done then it may
create problem or error in another phase.
• Requirement gathering is to be done initially but
it is not necessary to identify all the
requirements initially.
• Customers can view the system after
completion of all the phases and if he will not be
satisfy then if may leads to a serious problem.
8. This model combines all the elements of waterfall
model
Each linear sequence produces increments.
The first increment is called as CORE PRODUCT.
Core product addresses basic requirements which
is given to the users.
As a result of use a PLAN is developed for the next
increment.
The plan addresses modifications of the core
product to better meet the requirements of the
customers.
So ,that additional features and functionalities can
be added.
ADVANTAGES:
(1) This model is useful when more stuffing is not
10. It is an incremental process model in which there is
extremely short development cycle.
Using is model a fully functional system can be
developed within 60 to 90 days.
REQUIREMENT GATHERING: For identifying basic
requirements.
ANALYSES ANS PLANNING: Analyses of gathered
information is done and planning is done for carrying
out different development activities of system.
DESIGN PHASE: Various models are created such
as:-
business model, data model, process model.
BUILD PHASE: code is created and well tested to
detect and correct errors.
DEPLOYMENT PHASE:
Finally all the components are combined together.
13. PROTOTYPING MODEL
While developing software system it is often
needed to make modification in the
development process. In such cases
evolutionary process model is use.
Initially requirement gathering is done for that
software developer and communicate with each
other to identify requirement of the system.
14.
15. Advantages of prototype
model:
• Users are actively involved in the development
• Since in this methodology a working model of the
system is provided, the users get a better
understanding of the system being developed.
• Errors can be detected much earlier.
• Quicker user feedback is available leading to
better solutions.
• Missing functionality can be identified easily.
16. Disadvantages of Prototype
model:
• Leads to implementing and then repairing way
of building systems.
• Practically, this methodology may increase the
complexity of the system as scope of the system
may expand beyond original plans.
• Incomplete application may cause application
not to be used as the full system was designed
Incomplete or inadequate problem analysis.
17. SPIRAL MODEL
This model possessive iterative nature that
means in each iteration, it produce more
complete version of the software.
It is divided into number of activities called task
region.
Software team performs activities in spiral path in
clock vise direction.
19. Advantages of Spiral model:
•High amount of risk analysis hence, avoidance of
Risk is enhanced.
•Good for large and mission-critical projects.
•Strong approval and documentation control.
•Additional Functionality can be added at a later
date.
•Software is produced early in the software life
cycle.
20. Disadvantages of Spiral
model:
•Can be a costly model to use.
•Risk analysis requires highly specific expertise.
•Project’s success is highly dependent on the
risk analysis phase.
•Doesn’t work well for smaller projects.
21. CONCURRENT DEVELOPMENT
MODEL
• It represent schematically as a series of activity
and their associated states and that will trigger
transition from one to another.
• The modeling activity which existed in the null
state while communication between developers
and customer completed makes a transition in the
under development skill.