what is waterfall model?explain? what is v model? explain all phase?and the di

what is waterfall model?explain? what is v model? explain
all phase?and the difference between two model?

Question Posted / raja

3 Answers
14729 Views
CTD, CTS, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

what is waterfall model?explain? what is v model? explain all phase?and the difference between two..

V-Model

The V-model is a software development process which can be
presumed to be the extension of the waterfall model.
Instead of moving down in a linear way, the process steps
are bent upwards after the coding phase, to form the
typical V shape. The V-Model demonstrates the relationships
between each phase of the development life cycle and its
associated phase of testing.
The V-model deploys a well-structured method in which each
phase can be implemented by the detailed documentation of
the previous phase. Testing activities like test designing
start at the beginning of the project well before coding
and therefore saves a huge amount of the project time.

There are two type of phases:
1. Verification
2. Validation

Verification Phases:

Requirements analysis

In the Requirements analysis phase, the requirements of the
proposed system are collected by analyzing the needs of the
user(s). This phase is concerned about establishing what
the ideal system has to perform. However it does not
determine how the software will be designed or built.
Usually, the users are interviewed and a document called
the user requirements document is generated.
The user requirements document will typically describe the
system’s functional, physical, interface, performance,
data, security requirements etc as expected by the user. It
is one which the business analysts use to communicate their
understanding of the system back to the users. The users
carefully review this document as this document would serve
as the guideline for the system designers in the system
design phase. The user acceptance tests are designed in
this phase. See also functional requirements, and Non-
functional requirements

System Design:

Systems design is the phase where system engineers analyze
and understand the business of the proposed system by
studying the user requirements document. They figure out
possibilities and techniques by which the user requirements
can be implemented. If any of the requirements are not
feasible, the user is informed of the issue. A resolution
is found and the user requirement document is edited
accordingly.
The software specification document which serves as a
blueprint for the development phase is generated. This
document contains the general system organization, menu
structures, data structures etc. It may also hold example
business scenarios, sample windows, reports for the better
understanding. Other technical documentation like entity
diagrams, data dictionary will also be produced in this
phase. The documents for system testing is prepared in this
phase.

Architecture Design:

The phase of the design of computer architecture and
software architecture can also be referred to as high-level
design. The baseline in selecting the architecture is that
it should realize all which typically consists of the list
of modules, brief functionality of each module, their
interface relationships, dependencies, database tables,
architecture diagrams, technology details etc. The
integration testing design is carried out in this phase.

Module Design:

The module design phase can also be referred to as low-
level design. The designed system is broken up into smaller
units or modules and each of them is explained so that the
programmer can start coding directly. The low level design
document or program specifications will contain a detailed
functional logic of the module, in pseudocode - database
tables, with all elements, including their type and size -
all interface details with complete API references- all
dependency issues- error message listings- complete input
and outputs for a module. The unit test design is developed
in this stage.

Validation Phases:

Unit Testing:

In the V-model of software development, unit testing
implies the first stage of dynamic testing process.
According to software development expert Barry Boehm, a
fault discovered and corrected in the unit testing phase is
more than a hundred times cheaper than if it is done after
delivery to the customer.
It involves analysis of the written code with the intention
of eliminating errors. It also verifies that the codes are
efficient and adheres to the adopted coding standards.
Testing is usually white box. It is done using the Unit
test design prepared during the module design phase. This
may be carried out by software developers.

Integration Testing:

In integration testing the separate modules will be tested
together to expose faults in the interfaces and in the
interaction between integrated components. Testing is
usually black box as the code is not directly checked for
errors. It is done using the integration test design
prepared during the architecture design phase.

System Testing:

System testing will compare the system specifications
against the actual system. The system test design is
derived from the system design documents and is used in
this phase. Sometimes system testing is automated using
testing tools. Once all the modules are integrated several
errors may arise. Testing done at this stage is called
system testing. fg

User Acceptance Testing:

Acceptance testing is the phase of testing used to
determine whether a system satisfies the requirements
specified in the the requirements analysis phase. The
acceptance test design is derived from the requirements
document. The acceptance test phase is the phase used by
the customer to determine whether to accept the system or
not.

Waterfall model:

The waterfall model is a sequential development process, in
which development is seen as flowing steadily downwards
(like a waterfall) through the phases of Conception,
Initiation, Analysis, Design (validation), Construction,
Testing and maintenance.
The first formal description of the waterfall model is
often cited to be an article published in 1970 by Winston
W. Royce (1929–1995),although Royce did not use the
term "waterfall" in this article. Ironically, Royce was
presenting this model as an example of a flawed, non-
working model (Royce 1970). This is in fact the way the
term has generally been used in writing about software
development - as a way to criticize a commonly used
software practice.

Model:
In Royce's original waterfall model, the following phases
are followed in order:
1. Requirements specification
2. Design
3. Construction (AKA implementation or coding)
4. Integration
5. Testing and debugging (AKA Validation)
6. Installation
7. Maintenance

To follow the waterfall model, one proceeds from one phase
to the next in a purely sequential manner. For example, one
first completes requirements specification, which is set in
stone. When the requirements are fully completed, one
proceeds to design. The software in question is designed
and a blueprint is drawn for implementers (coders) to
follow — this design should be a plan for implementing the
requirements given. When the design is fully completed, an
implementation of that design is made by coders. Towards
the later stages of this implementation phase, disparate
software components produced are combined to introduce new
functionality and remove errors.
Thus the waterfall model maintains that one should move to
a phase only when its preceding phase is completed and
perfected. However, there are various modified waterfall
models (including Royce's final model) that may include
slight or major variations upon this process.

Regards,
Anoop

Is This Answer Correct ?

17 Yes

5 No

what is waterfall model?explain? what is v model? explain all phase?and the difference between two..

Answer / preeti

waterfall model model follows the folowing steps:
requirement-->analysis-->Design-->coding-->Testing--
>Maintainance-->final product.testing is the fifth step
after the coding been performed.

V Model-Verification&Validation model.
customer requirement<------------->Acceptance testing
specification <-------------->System testing.
High level design<--------->Integration Testing.
Low level design<------->Unit Testing.
Coding

as given here in V model testing is done at every
stage.right from Initial Requirement phase till end phase.
Verification & validation are performed end to end.

Is This Answer Correct ?

12 Yes

2 No

what is waterfall model?explain? what is v model? explain all phase?and the difference between two..

Answer / kishor jahan

your answer correct

Is This Answer Correct ?

3 Yes

0 No

Post New Answer