Software Development Life Cycle

What are the Software Development Life Cycle (SDLC) phases??

There are various software development approaches defined and designed which are used/employed during development process of software, these approaches are also referred as “Software Development Process Models” (e.g. Waterfall model,incremental model, V-model, iterative model, etc.). Each process model follows a particular life cycle in order to ensure success in process of software development.

You might be surprised, but it’s true that many of them who are into software development still don’t know as to what is software development life cycle. It’s quite strange, however, is the fact. Software development life cycle is nothing but a step-by-step process involved in the development of a software product. It’s also denoted as software development process in certain cities of the world. The entire process is usually classified into a set of steps and a particular operation will be carried out in each of the steps

Software life cycle models describe phases of the software cycle and the order in which those phases are executed. Each phase produces deliverables required by the next phase in the life cycle. Requirements are translated into design. Code is produced according to the design which is called development phase. After coding and development the testing verifies the deliverable of the implementation phase against requirements.

There are following six phases in every Software development life cycle model:

1. Requirement gathering and analysis
2. Design
3. Implementation or coding
4. Testing
5. Deployment
6. Maintenance

1) Requirement gathering and analysis:  Business requirements are gathered in this     phase. This phase is the main focus of the project managers and stake holders. Meetings with managers, stake holders and users are held in order to determine the requirements like; Who is going to use the system? How will they use the system?  What data should be input into the system?  What data should be output by the system?  These are general questions that get answered during a requirements gathering phase. After requirement gathering these requirements are analyzed for their validity and the possibility of incorporating the requirements in the system to be development is also studied.

Finally, a Requirement Specification document is created which serves the purpose of guideline for the next phase of the model.

2)  Design:  In this phase the system and software design is prepared from the requirement specifications which were studied in the first phase. System Design helps in specifying hardware and system requirements and also helps in defining overall system architecture. The system design specifications serve as input for the next phase of the model.

The design phase begins, once the analysis or investigation is over. The main purpose is to create the architecture of the total system. This is one of the vital stages of the process and is known to be a benchmark stage, since the errors are carried out until this stage and and can also be cleaned during this stage.

One can totally classify the entire process as; planning, analysis, design, development, implementation, testing, deployment, maintenance. Each of these steps of the process possess its own significance and plays a vital part. The description of some of the steps can give a better understanding .

This is the initial and primary stage in the development and one of the most vital stages. The primary aim is to plan the total project and to estimate the merits as well as the demerits of the project. This phase includes the definition of the intended system, development of the project plan and parallel management of the plan right through the proceeding

3)  Implementation / Coding:  On receiving system design documents, the work is divided in modules/units and actual coding is started. Since, in this phase the code is produced so it is the main focus for the developer. This is the longest phase of the software development life cycle.

4)  Testing:  After the code is developed it is tested against the requirements to make sure that the product is actually solving the needs addressed and gathered during the requirements phase. During this phase unit testing, integration testing, system testing, acceptance testing are done.

In software development life cycle, this phase is considered to be one of the final stages, and also the phase where the final adjustments are made prior to presenting the totally developed software to the end user. Here, the tester encounters the problem of removing the bugs and logical error

5)  Deployment: After successful testing the product is delivered / deployed to the customer for their use.

6) Maintenance: Once when the customers starts using the developed system then the actual problems comes up and needs to be solved from time to time. This process where the care is taken for the developed product is known as maintenance.