Software Development Life Cycle (SDLC)

Table of Contents

Introducton

The Software Development Life Cycle (SDLC) is a process for producing high quality software by involving development phases like requirement analysis, feasibility study, design, code, testing, and deployment.

SDLC specifies each stage of software development, ensuring that the product meets technical and user objectives, stays within budget, and is delivered on time. The Software Development Life Cycle (SDLC) is a series of processes that give a framework for planning and regulating the development of an information system.

It covers everything from the initial feasibility investigation to the maintenance of the completed application. SDLC’s primary purpose is to develop high-quality software that meets or exceeds customer expectations, is completed on time and within budget, and runs effectively and efficiently in the current and planned IT infrastructure.

There is a huge benefit to using the software development life cycle. It helps you decrease the project risk. The SDLC aims to produce high-quality software that meets the requirements of customer expectations, reaches completion within time and cost estimates. The figure below shows the different phases of the software development life cycle (SDLC).

Phases of the Software Development Life Cycle (SDLC)

Requirement analysis

Requirement analysis is the first phase and an important stage in SDLC. It starts with gathering the requirements from customers. This phase includes background reading, planning, goal, schedule, and budget requirements of the system. It is conducted by the senior team members. This phase provides a clear scope of the entire project. Also, system analysis is done which is the study of a problem domain. During this phase, all system requirements are obtained and recorded.

Analysts collaborate with stakeholders such as clients, users, and developers to determine the needed functionality. A new system cannot be developed without analyzing the resources, ideas, effectiveness, and limitations of the existing system. The necessity of system analysis can be understood by interviewing different people. While building the required system, system analysis is necessary while implementing new ideas to solve the existing problems. This stage is the first stage of the SDLC.

Feasibility Study

After the requirement analysis is completed, the next step of the software development cycle is the feasibility study. Feasibility is the measure of how beneficial a system will be to an organization. It is the process where the feasibility is measured. There can be many solutions to a system and the feasibility study selects the best one that meets the software requirement specification (SRS). The feasibility study must consider the following areas:

Operational Feasibility – It is a measure of how well the solution will work in an organization and people feel about the system. It is a criterion to measure the urgency of the problem.

Technical Feasibility – It is the measure of the practicality of a specific technical solution and the availability of the technical resource and expertise. In this feasibility determination is made of the system can be developed and implemented using existing technology.

Economic Feasibility – It refers to the analyzing of how beneficial will be the system with regards to time, money and other resource required.

Schedule Feasibility – It is the measure of how responsible the project timetable is. Projects are usually initiated with specific deadlines.

Design

With the requirements specified, the design phase focuses on how to develop the software. It is an important part of the software development life cycle. The design is done according to the gathered requirements. This phase develops the technical blueprint and specification required to implement the database, programs, and user interfaces for the system. Necessary software and hardware are purchased in this phase. For design, system designers use various types of design tools such as Charts, Data Flow Diagram, ER Diagram, decision table, UML, context diagram, etc. This involves both high-level system architecture and specific component-level design.

Types of Design:

High-level design (HLD) encompasses architecture, technological stack, database design, and system interfaces.

Low-level design (LLD) refers to the logic of individual components, algorithms, and user interface design.

Development (or Coding)

System implementation refers to putting the tested system into operation. The final software is released. The main component of every software product is people. Training should be given as per the needs of the system user. Some system users may be reluctant to replace the old system with the new one completely. This is the stage where developers start writing code based on the design documents. This phase is typically the longest and requires collaboration among programmers, designers, and engineers. Programming languages, frameworks, and tools vary based on project needs. Modern teams often use version control systems like Git and platforms like GitHub, GitLab, or Bitbucket.

Testing

After the development, testing is done. System design is the process of analyzing the system to find errors. This phase is the most complex and time-consuming phase of the software development life cycle. Testing methods like whitebox testing, black box testing, unit testing, integration testing, system testing, performance and security testing, etc. There are two popular testing methods.

Black box testing

In black box testing, the internal workings of the item being tested are not known by the tester. The tester is only concerned about the outcomes from the system when some specific inputs are given.

White box testing

In white box testing, internal working of the items, programming language code, being tested is visible. The tester uses knowledge of programming code to examine outputs.

Implementation

Maintenance

After the system is implemented, the users may face various difficulties or new errors. This is the last phase of the software development life cycle. There is a need of system maintenance and review. The maintenance can be bug fixing because some parts are not tested properly. Maintenance can be upgrading the system to the new versions, tackling all the bugs and errors. Enhancing the system by adding new security features to the existing system. This is the last stage of SDLC.

SDLC offers improved planning and control.

Improved Planning and Control – Timelines, budgets, and resources can all be managed more effectively with structured phases.
Enhanced Quality Assurance – Rigorous testing guarantees a high-quality product.
Clear communication – Defined responsibilities and deliverables facilitate team coordination and stakeholder collaboration.
Risk Management – Identifying risks early in the planning phase aids mitigation.
User-Centric – Agile methods include customer feedback constantly.

Challenges in SDLC

Changing Requirements – Scope creep has the potential to affect project timetables and finances.
Lack of Stakeholder Involvement – Poor communication might result in unmet requirements.
Inadequate testing can lead to unstable products.
Poor documentation – Makes future maintenance and updates more difficult.
Time and budget constraints – Pressure to deliver quickly can impair quality.

Emerging Trends in SDLC

DevOps Integration
Continuous integration (CI) and continuous deployment (CD) procedures are eroding the distinction between development and operations.
AI and Automation
AI-powered testing and code creation technologies are accelerating the development process.
Low-Code/No-Code Platforms
Enable rapid development with minimal manual coding.
Cloud-Native Development
Applications are increasingly being developed to run in cloud environments using containers and microservices.
Security by Design
Security is increasingly being integrated throughout the process, rather than just at the conclusion.