Software Development Life Cycle (SDLC) Models

In this post I will discuss few Software Development Life Cycle (SDLC) Models briefly
and talk about their advantages and disadvantages.

Prototype Model

A prototype model focuses on developing the software little by little and tested
in a real time environment with the customers in mind (“SDLC prototype model”, n.d).

Advantages of prototype model are it has its time frame of development with more
focus on development of actual software rather than spending more time on
documentation resulting in releasing the software in advance, reduced man hours,
the software is created with more user feedbacks (“SDLC prototype model”, n.d).

Disadvantages of prototype model since the software is built with no stages most
of the beginning stages of the software are not complete, prototype changes from
time to time resulting in complexity in making documentation on the software and
integration might be hard with this model (“SDLC prototype model”, n.d).

V-Shaped Model

A V-Shaped Model is similar to Waterfall Model with regards to sequential path
of execution of processes one can move a step ahead only when previous step is
completed and testing is more highlighted in this model (Lewallen, 2005).

Advantages of V-Shaped model are it is easy and simple to use and each step
delivers a specific result as tests are planed earlier than in waterfall model
there are more chances for success, and when small projects are considered this
model will work well for them (Lewallen, 2005).

Disadvantages of V-Shaped model are it is very inflexible and thus may lead to
more expense and during the testing phases this model has no clear picture (Lewallen, 2005).

W-Shaped Model

W-Shaped Model removes the disadvantage from Waterfall Model and V-Shaped Model
where the testing is followed after the implementation, the association between
the various stages and their result for further testing undertakings is not
explained. Based on the V-Shaped Model the W-Shaped Model improves the meaning
of testing specific tasks (Leithold, 2005).

Advantages of W-Shaped model are the testing process is parallel to the
development process; testers and developers are given specific tasks as the
project moves forward resulting them being equally involved, and in the testing
phase the developers fix the bugs (Leithold, 2005).

Disadvantages of W-Shaped model the time and personnel are impracticable and in
practice there is much more relationship between different activities (Leithold, 2005).

Incremental Model

When the life cycle of waterfall model is applied iteratively, it results in
Incremental Model and each of these iterations goes through requirements,
design, implementation and testing (Lewallen, 2005).

Advantages of Incremental Model are the working software is produced faster and
is more flexible resulting in lower costs for changes in requirements, it is
easy to debug since the iterations are smaller and are easy to manage (Lewallen, 2005).

Disadvantages of Incremental Model are there is no account of intersecting of
iterations as they are inflexible, the overall system architecture requirements
aren’t gathered in the beginning of the software development which may lead to
problem in the software life cycle (Lewallen, 2005).

COCOMO Estimating Model

COCOMO stands for constructive cost model, it’s a software cost estimation model
which uses regression formula with parameters based on historic data (“Software
project management”, n.d.).

Advantages of COCOMO estimating model are it is based on facts and easy to
understand how it works, explains many reasons that affect cost of the project
and since it works on historical data it is more predictable and accurate
(“Software project management”, n.d.).

Disadvantages of COCOMO estimating model are it ignores requirements,
documentation, hardware issues, personnel turnover levels, customer skills,
cooperation, knowledge and other parameters. It oversimplifies the impact of
safety/security aspects and is dependent on the amount of time spent in each
phase (“Software project management”, n.d.).


Geek Interview. (n.d). SDLC – prototype model. Retrieved from

Hot Recruiter. (n.d). Software project management. Retrieved from

Leithold, A. (July, 2007). Structured testing in practice. Norderstedt, Germany:
Druck und Bindung. ISBN 978-3-638-8946293

Lewallen, R. (July, 2005). Software development life cycle models. Retrieved

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