Software Development Life Cycle (SDLC)

Phases of SDLC (Software Development Life Cycle):

 The different phases of SDLC are —–

Planning :

The first phase of SDLC is planning, where the project scope is defined and the objectives are set. This phase involves determining the feasibility of the project estimating the resources required identifying potential risks and creating a project plan.

The planning stage (also called the feasibility stage) is the phase in which developers will plan for the project. Project planning is a vital role in the software development lifecycle since this is the part where the team estimates the cost and defines the requirements of the software. This typically includes resource allocation, capacity planning, and project scheduling and cost estimation.

During the planning phase, the development team collects input from stakeholders involved in the project; customers, sales, internal and external experts, and developers. This input is synthesized into a detailed definition of the requirements for creating the desired software. The team also determines what resources are required to satisfy the project requirements, and then infers the associated cost.

The planning phase will determine project goals and establish a high-level plan for the intended project. Planning should clearly define the scope and purpose of the application 

Requirements gathering & Analysis :

This phase involves gathering and analyzing the requirements of the software to be developed. The project team analyzes the business requirements, functional requirements and technical requirements and converts them into a detailed system specification document. The document serves a s a blueprint for the design and development of the software.

In this phase, all the relevant information is collected from the customer to develop the product as per their expectation. This is done to clearly understand the customer requirements. Discuss each detail and specification of the product with the customer.

Project Manager set up a meeting with the customer to gather all the information like what the customer wants to build, who will be the end-user, what is the purpose of the product. Before building a product a core understanding or knowledge of the product is very important.

Once the requirement gathering is done, the development team will then analyze the requirements. Requirement documentation is very important activity after the requirement gathering and analysis. This is a way to represent requirements in a consistent format.

During this activity, the user requirements are systematically organized into a Software Requirement Specification (SRS) documents.  This document should be thoroughly understood by the developers and also should be reviewed by the customer for future reference.

Design :

In this phase, the software architecture is designed. The development team creates a detailed design for the software system based on the requirements gathered in the previous phase. Once the requirements are understood, software architects and developers can begin to design the software. The goal of design phase is to transform the requirements specified in the SRS documents into a structure that is suitable for implementation in some programming languages.

In this phase, the development team creates a detailed design document that outlines how the software will be built. The design document includes details about the software architecture, data models, algorithms and user interface.

In other words, Software design is the process of designing the architecture, components, modules, interfaces for a system to satisfy specified requirements.

This phase includes Algorithms, Flowchart, Pseudo-code, Screen layouts and other necessary documentation. The organization also creates user interaction interfaces, data models, and entity relationship diagrams (ERDs) in this phase.

Coding or implementation :

The implementation phase involves the actual coding of the software system. The design documents from the previous phase are used to create the software code. The software is built according to the design document and the development team uses a variety of programming languages, tools and frameworks to write the code.

Coding or implementation starts once the developer gets the design document. The Software design is translated into source code. In this stage, developers start builds the entire system by writing code using the chosen programming language.

This is the actual writing of the program. A small project might be written by a single developer while a large project might be broken up and worked by several teams.

The system first developed in small programs called modules. In the coding phase, tasks are divided into units or modules and assigned to the various developers.

Testing :

In this phase, the software is tested to ensure that it meets the requirements outlined in the planning analysis phases. Building software is not the end. Now it must be tested to make sure that there aren’t any bugs. Testing starts once the coding is complete and the modules are released for testing. Software testing involves examining and checking the software, through different testing process. The testing is done to ensure that the entire application works according to the customer requirements. The testing team creates test cases to ensure that the software meets the specifications outlined in the designed document.

After the development of the software, there can be many defects in the software or software may not work as they are expected. Testing is carried out to verify the entire system. In this phase, the developed software is tested thoroughly and any defects found are assigned to developers to get them fixed. The aim of the testing is to find out the gaps and defect within the system and also to check whether the system is running according to the requirement of the customer.

Testing is an important part of the project because it helps to improve the quality of the project. In this stage, all the pieces of code are tested to verify and validate a software product. The testing team tests the functionality of the entire system.

Deployment :

Once the software system has passed testing, it is deployed to the production environment. This involves installing the software on the target hardware , configuring the software and verifying that the system operates correctly.

In the deployment phase, the application is made available to the users. Once the software has been tested and is ready for deployment, it is released to the client or end-users to use. This deployment can be done in different ways, such as a direct installation on the user’s computer, deployment on a server or through the cloud. This phase also involves providing user training and support.

Maintenance :

The final phase of the SDLC is maintenance. This phase involves maintaining and updating the software system after it has been deployed. The maintenance phase is the last but important phase of SDLC. The SDLC doesn’t end when software reaches the market. Once the product has been delivered to the customer, task of maintenance starts as when the customer will come up with an error, the issue should be fixed from time to time. In this phase, the software is maintained and updated as needed to ensure that it continues to function properly

This phase involves maintaining and enhancing the software to ensure that it continues to meet the user’s requirements. Maintenance activities includes fixing bugs, performance improvements, adding new features and addressing security vulnerabilities.. Software maintenance is modification of a software product after delivery to correct faults, to improve performance, or to adopt the product to a modified environment. According to the changing user end environment or technology, the software is updated timely.

Maintenance is the backbone of the software success. When software is developed, then software needs to be modified from time-to-time to keep it up to date with environment changes and changing the user requirements. The maintenance phase continues throughout the life cycle of the software.

Furthermore, developers are responsible for implementing any changes that the software might need after deployment.

Now a days, the companies are paying more attention towards maintenance of their product. For example, Windows and several antivirus software are regularly updated to maintain their performance.