Agile model believes that every project needs to be handled
differently and the existing methods need to be tailored to best suit the
project requirements. In agile the tasks are divided to time boxes (small time
frames) to deliver specific features for a release.
Iterative approach is taken and working software build is
delivered after each iteration. Each build is incremental in terms of features;
the final build holds all the features required by the customer.
Here is a graphical illustration of the Agile Model:
Agile
thought process had started early in the software development and started
becoming popular with time due to its flexibility and adaptability.
Following
are the Agile Manifesto working principles:
Individuals
and interactions
- in agile development, self-organization and motivation are important, as are
interactions like co-location and pair programming.
Working
software - Demo
working software is considered the best means of communication with the
customer to understand their requirement, instead of just depending on
documentation.
Customer
collaboration
- As the requirements cannot be gathered completely in the beginning of the
project due to various factors, continuous customer interaction is very
important to get proper product requirements.
Responding
to change - agile
development is focused on quick responses to change and continuous development.
Agile
Vs Traditional SDLC Models
Agile is
based on the adaptive software development methods where as the traditional
SDLC models like waterfall model is based on predictive approach.
Predictive
teams in the traditional SDLC models usually work with detailed planning and
have a complete forecast of the exact tasks and features to be delivered in the
next few months or during the product life cycle. Predictive methods entirely
depend on the requirement analysis and planning done in the beginning of cycle.
Any changes to be incorporated go through a strict change control management
and prioritization.
Agile uses
adaptive approach where there is no detailed planning and there is clarity on
future tasks only in respect of what features need to be developed. There is
feature driven development and the team adapts to the changing product
requirements dynamically. The product is tested very frequently, through the
release iterations, minimizing the risk of any major failures in future.
Customer
interaction is the backbone of Agile methodology, and open communication with
minimum documentation are the typical features of Agile development
environment. The agile teams work in close collaboration with each other and
are most often located in the same geographical location.
Agile
Model Advantages and Disadvantages
Agile
methods are being widely accepted in the software world recently, however, this
method may not always be suitable for all products. Here are some advantages
and disadvantages of the agile model.
Following
table lists out the advantages and disadvantages of Agile Model:
Advantages
|
Disadvantages
|
Is a
very realistic approach to software development
Promotes
teamwork and cross training.
Functionality
can be developed rapidly and demonstrated.
Resource
requirements are minimum.
Suitable
for fixed or changing requirements
Delivers
early partial working solutions.
Good
model for environments that change steadily.
Minimal
rules, documentation easily employed.
Enables
concurrent development and delivery within an overall planned context.
Little
or no planning required
Easy to
manage
Gives
flexibility to developers
|
Not
suitable for handling complex dependencies.
More
risk of sustainability, maintainability and extensibility.
An
overall plan, an agile leader and agile PM practice is a must without which
it will not work.
Strict
delivery management dictates the scope, functionality to be delivered, and
adjustments to meet the deadlines.
Depends
heavily on customer interaction, so if customer is not clear, team can be
driven in the wrong direction.
There is
very high individual dependency, since there is minimum documentation
generated.
Transfer
of technology to new team members may be quite challenging due to lack of
documentation.
|
