SOFTWARE DEVELOPMENT LIFE CYCLE METHODOLOGY
What is Software Development Life Cycle(SDLC) ?
SDLC is a process used by software developer for designing ,developing and test high quality software project in the industry. It is also called as Software Development Process. SDLC has the various stages like figure 1.

SDLC Methodology
Developer use SDLC methodology for get high quality software as quickly and cost-effectively as possible and also all methodology has advantages and disadvantage. Most suitable method depend on the project attribute.
In industry has more SDLC methodology and also use combined models ,
Examples …..
— — — — — Waterfall — — — — — -
is a waterfall SDLC model where the development process is like the flow, moving step by step through the phases of analysis, projection, realization, test, implementation and support. This SDLC model involves progressive execution of each step in full. This process is strictly documented and predefined with the expected functionality for each phase of this software development life cycle model.

ADVANTAGES
Simple to use and understand
Management simplicity thanks to its rigidity: every phase has a defined result and process review
Development stages go one by one
Perfect for the small or mid-sized projects where requirements are clear and not equivocal
Easy to determine the key points in the development cycle
Easy to classify and prioritize tasks
DISADVANTAGES
The software is ready only after the last stage is over
High risks and uncertainty
Not the best choice for complex and object-oriented projects
Inappropriate for the long-term projects
The progress of the stage is hard to measure while it is still in the development
Integration is done at the very end, which does not give the option of identifying the problem in advance
— — — — — Spiral — — — — — -

ADVANTAGES
Lifecycle is divided into small parts, and if the risk concentration is higher, the phase can be finished earlier to address the treats
The development process is precisely documented yet scalable to the changes
The scalability allows to make changes and add new functionality even at the relatively late stages
The earlier working prototype is done — sooner users can point out the flaws
DISADVANTAGES
Can be quite expensive
The risk control demands involvement of the highly-skilled professionals
Can be ineffective for the small projects
Big number of the intermediate stages requires excessive documentation
— — — — — V-shaped — — — — — -

ADVANTAGES
Every stage of V-shaped model has strict results so it’s easy to control
Testing and verification take place in the early stages
Good for the small projects, where requirements are static and clear
DISADVANTAGES
Lack of the flexibility
Bad choice for the small projects
Relatively big risks
— — — — — Agile — — — — — -

ADVANTAGES
Corrections of functional requirements are implemented into the development process to provide the competitiveness
Project is divided by short and transparent iterations
Risks are minimized thanks to the flexible change process
Fast release of the first product version
DISADVANTAGES
Difficulties with measuring the final cost because of permanent changes
The team should be highly professional and client-oriented
New requirements may conflict with the existing architecture
With all the corrections and changes there is possibility that the project will exceed expected time