SDLC: Phases & Models of Software Development Life Cycle

Software Development Life Cycle
Software Development Life Cycle

Software development life cycle: A software life cycle model (likewise named process model) is a pictorial and diagrammatic representation of the software life cycle. A life cycle model addresses every one of the techniques needed to make a software product transit through its life cycle stages. It additionally catches the structure wherein these strategies are to be attempted.

In other words, a life cycle model maps the different exercises performed on a software item from its beginning to retirement. Different life cycle models may plan the vital development exercises to stages in different ways. In this manner, no element which life cycle model is followed, the fundamental exercises are contained in all life cycle models however the activity might be done in distinct orders in various life cycle models. During any life cycle stage, more than one action may likewise be done.

In this article, you will learn-

What is SDLC?

SDLC is a systematic process for building software that guarantees the quality and accuracy of the software built. SDLC process plans to deliver high-quality software that meets client expectations. The system development ought to be finished in the pre-defined time frame and cost. SDLC comprises of a detailed plan which explains how to plan, build , and keep up specific software. Every phase of the SDLC life Cycle has its own process and deliverables that feed into the next phase. SDLC represents Software Development Life Cycle and is additionally referred to as the Application Development life-cycle


Here, are prime reasons why SDLC is significant for developing a software system.

• It offers a basic for project planning, scheduling, and estimating

• Provides a system for a standard set of activities and deliverables

• It is a mechanism for project tracking and control

• Increases visibility of project intending to all involved stakeholders of the development process

• Increased and improve development speed

• Improved clients relations

• Helps you to diminish project risk and project management plan overhead

SDLC Phases

The whole SDLC process divided into the accompanying SDLC steps:

SDLC Phases

• 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

In this tutorial, I have explained all these Software Development Life Cycle Phases

Phase 1: Requirement collection and analysis

The necessity is the first stage in the SDLC process. It is conducted by the senior colleagues with inputs from all the stakeholders and domain experts in the industry. Planning for the quality assurance prerequisites and recognization of the risks involved is additionally done at this stage.

This stage gives a more clear image of the scope of the whole project and the expected issues, opportunities, and directives which triggered the project.

Prerequisites Gathering stage need teams to get detailed and exact necessities. This assists companies to finalize the necessary timetable to complete the work of that framework.

Phase 2: Feasibility study

When the prerequisite analysis phase is finished the next sdlc step is to define and document software needs. This process conducted with the assistance of ‘Software Requirement Specification’ document otherwise called ‘SRS’ document. It incorporates everything that which ought to be designed and created during the project life cycle.

There are fundamentally five sorts of practicalities checks:

• Economic: Can we finish the task inside the spending plan or not?

• Legal: Can we handle this project as cyber law and other regulatory framework/compliances.

• Operation feasibility: Can we create operations which is normal by the client?

• Technical: Need to check whether the current computer system can support the software

• Schedule: Decide that the project can be finished inside the given timetable or not.

Phase 3: Design

In this third phase, the system and software design documents are set up according to the prerequisite particular document. This helps define overall system architecture.

This design phase serves as input for the next phase of the model.

There are two sorts of design documents developed in this phase:

High-Level Design (HLD)

• Brief description and name of each module

• An outline about the usefulness of each module

• Interface relationship and dependencies between modules

• Database tables distinguished alongside their key elements

• Complete architecture diagrams alongside technology details

Low-Level Design(LLD)

• Functional logic of the modules

• Database tables, which incorporate sort and size

• Complete detail of the interface

• Addresses all types of dependency issues

• Listing of error messages

• Complete input and outputs for every module

Phase 4: Coding

When the system design phase is finished, the next phase is coding. In this phase, developers start build the whole system by writing code using the picked programming language. In the coding phase, tasks are divided into units or modules and assigned to the different developers. It is the longest phase of the Software Development Life Cycle Process.

In this phase, Developer needs to follow certain predefined coding rules. They likewise need to use programming tools like compiler, interpreters, debugger to produce and execute the code.

Phase 5: Testing

When the software is finished, and it is deployed in the testing environment. The testing team begins testing the usefulness of the whole system. This is done to verify that the whole application works as per the customer necessity.

During this phase, QA and testing team may discover some bugs/defects which they communicate to developers. The development team fixes the bug with and send back to QA for a re-test. This process proceeds until the software is without bug, stable, and working as per the business needs of that system.

Phase 6: Installation/Deployment

When the software testing phase is finished and no bugs or errors left in the system then the final deployment process begins. Based on the feedback given by the project manager, the final software is released and checked for deployment issues assuming any.

Phase 7: Maintenance

When the system is deployed, and clients begin using the developed system, following 3 activities happen

• Bug fixing – bugs are reported for due to certain situations which are not tried at all

• Upgrade – Upgrading the application to the fresher versions of the Software

• Enhancement – Adding some new highlights into the existing software

The main focus of this SDLC phase is to guarantee that requirements keep on being met and that the system keeps on proceeding according to the detail referenced in the first phase.

Popular SDLC models

Here, are some of the most significant models of Software Development Life Cycle (SDLC):

Waterfall model in SDLC

The waterfall is a generally acknowledged SDLC model. In this methodology, the entire process of the software development is divided into different phase of SDLC. In this SDLC model, the result of one phase acts as the input for the next phase.

This SDLC model is documentation-intensive, with earlier phase documenting what need be acted in the subsequent phase.

Incremental Model in SDLC

The incremental model is not a separate model. It’s essentially a series of waterfall cycles. The necessities are divided into groups toward the beginning of the project. For each group, the SDLC model is followed to develop software. The SDLC life cycle process is repeated, with each release adding more usefulness until all prerequisites are met. In this strategy, every cycle act as the maintenance phase for the previous software release. Adjustment to the incremental model allows development cycles to cover. After that subsequent cycle may start before the previous cycle is finished.

V-Model in SDLC

In this sort of SDLC model testing and the development, the phase is arranged in parallel. In this way, there are verification phases of SDLC on the side and the validation phase on the other side. V-Model joins by Coding phase.

Agile Model in SDLC

Agile methodology is a training which promotes proceed interaction of development and testing during the SDLC process of any project. In the Agile technique, the whole project is divided into small incremental builds. All of These builds are given in iterations, and each iteration keeps going from one to three weeks.

Spiral Model

The spiral model is a risk-driven process model. This SDLC testing model assists the team to adopt elements of one or more interaction models like a waterfall, incremental, waterfall, and so forth

This model adopts the best highlights of the prototyping model and the waterfall model. The spiral procedure is a combination of fast prototyping and simultaneousness in design and development exercises.


• The Software Development Life Cycle (SDLC) is a systematic process for building software that guarantees the quality and accuracy of the software built

• The full form SDLC is Software Development Life Cycle or Systems Development Life Cycle.

• SDLC in software engineering gives a structure to a standard arrangement of exercises and deliverables

• Seven different SDLC stages are 1) Requirement collection and analysis 2) Feasibility study: 3) Design 4) Coding 5) Testing: 6) Installation/Deployment and 7) Maintenance

• The senior colleagues conduct the requirement analysis phase

• Feasibility Study stage incorporates everything which ought to be designed and developed during the project life cycle

• In the Design stage, the system and software design document are set up according to the prerequisite determination document

• In the coding stage, developers start build the whole system by writing code using the picked programming language

• Testing is the next stage which is conducted to confirm that the whole application works as per the client necessity.

• Installation and deployment face starts when the software testing stage is finished, and no bugs or error left in the system

• Bug fixing, upgrade, and engagement activities covered in the maintenance face

• Waterfall, Incremental, Agile, V model, Spiral, are a portion of the well known SDLC models in software engineering

SDLC in software testing comprises of a detailed arrangement which explains how to plan, build, and maintain specific software.


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salman khan

Written by worldofitech

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