The Phases of the Software Development Life cycle

Software development life cycle(SLDC) is also known as Software development or Application Development Life Cycle.

OVERVIEW

SLDC is a software that that helps in developing , designing and testing high quality software whose primary goal is to establish the quality and faultlessness of the software unit that meets or exceeds the customers expectations , is cost efficient and reach completion within time. It has six stages that ensures the success of SLDC. the stages are: Planning and requirement analysis, Defining requirements, designing and product architecture, Building and development of the product, Testing of the product and Development in the market and maintenance. There are many SLDC models that are popular and important for it's growth such as waterfall model, iterative model, spiral model, v model etc. Moreover, there are also certain phases of SLDC that are equally important. They are Requirement collection and analysis, Feasibility study, Design, Coding, Testing, Installation/Deployment and Maintenance. The SDLC is not a methodology , but rather a description of the phases in the life cycle of a software application.

What is SLDC?

Software development life cycle(SLDC) is also known as Software development or Application Development Life Cycle.

It is a supporting structure that defines the tasks performed at each step in the process of software development . This software is generally used in industry to design, develop and test high quality Software's. Its primary goal is to establish the quality and faultlessness of the software built.

What does SLDC aim for?

The SDLC's main focus is to produce a high-quality software that meets or transcends customer expectations, reaches completion within times and cost estimates. It aims to be the standard that defines all the tasks required for developing and maintaining the software. SDLC is a process followed for a software project, within a software organization. It consists of a detailed plan describing how to develop, maintain, replace and alter or enhance specific software.

Why SLDC?

· It offers a basis for project planning, scheduling, and estimating

· Provides a framework for a standard set of activities and deliverables

· It is a mechanism for project tracking and control

· Increases visibility of project planning to all involved stakeholders of the development process

· Increased and enhance development speed

· Improved client relations

· Helps you to decrease project risk and project management plan overhead

A typical Software Development Life Cycle consists of the following stages:

Stage 1: Planning and Requirement Analysis

Requirement analysis is the most essential and fundamental stage in SDLC. It is performed by the senior members of the team by taking the inputs from the customer, the sales department, market surveys and domain experts in the industry. This information is then used to plan the basic project approach and to conduct product feasibility study in the economical, operational and technical areas.

In the planning stage, identification of the risks associated with the project and the requirements for the assurance of quality is done. The end result of their evaluation exercise and exploring the feasibility is to define the various technical approaches that can be considered to implement the project successfully with minimum risks and maximum profit.

Stage 2: Defining Requirements

Once the requirement analysis is done, the next step is to clearly define and document the product requirements and get them approved from the customer or the market analysts. This is done through an SRS (Software Requirement Specification) document which consists of all the product requirements to be designed and developed during the project life cycle.

Stage 3: Designing the Product Architecture

SRS is the reference for product architects to come out with the best architecture for the product to be developed. Based on the requirements specified in SRS, usually more than one design approach for the product architecture is proposed and documented in a Design Document Specification(DDS). This DDS is reviewed by all the important stakeholders and based on various parameters as risk assessment, product robustness, design modularity, budget and time constraints, the best design approach is selected for the product. A design approach clearly defines all the architectural modules of the product along with its communication and data flow representation with the external and third party modules . The internal design of all the modules of the proposed architecture should be clearly defined with the minutest of the details in DDS.

Stage 4: Building or Developing the Product

In this stage of SDLC the actual development starts and the product is built. The programming code is generated as per DDS during this stage. If the design is performed in a detailed and organized manner, code generation can be accomplished without much hassle. Developers must follow the coding guidelines defined by their organization and programming tools like compilers, interpreters, debuggers, etc. are used to generate the code. Different high level programming languages such as C, C++, Pascal, Java and PHP are used for coding. The programming language is chosen with respect to the type of software being developed.

Stage 5: Testing the Product

This stage is usually a subset of all the stages as in the modern SDLC models, the testing activities are mostly involved in all the stages of SDLC. However, this stage refers to the testing only stage of the product where product defects are reported, tracked, fixed and retested, until the product reaches the quality standards defined in the SRS.

Stage 6: Deployment in the Market and Maintenance

Once the product is tested and ready to be deployed it is released formally in the appropriate market. Sometimes product deployment happens in stages as per the business strategy of that organization. The product may first be released in a limited segment and tested in the real business environment (UAT- User acceptance testing).

After that, based on the feedback, the product may be released as it is or with some suggested enhancements in the targeting market segment. After the product is released in the market, its maintenance is done for the existing customer base.

There are certain SLDC models that are most important and popular. Some of them are:-

· Waterfall Model

· Iterative Model

· Spiral Model

· V-Model

· Big Bang Model

Other related methodologies are Agile Model, RAD Model, Rapid Application Development and Prototyping Models.

Phases of SLDC

Phase 1: Requirement collection and analysis

Phase 2:Feasibility study

Phase 3: Design

Phase 4: Coding

Phase 5: Testing

Phase 6: Installation/Deployment

Phase 7: Maintenance