Software Testing Tutorial #6 - Software Development Life Cycle (SDLC)

Summary

This tutorial explains the Software Development Life Cycle (SDLC), which outlines the steps followed in software development. It covers key phases: requirement gathering, analysis, design, development, testing, deployment, and maintenance. The video emphasizes how each phase is critical to delivering a successful software product, with a focus on different approaches like Waterfall, V-Model, and Agile. The instructor also touches on how SDLC phases are foundational for understanding the Software Testing Life Cycle (STLC), making it essential for software testers to grasp these concepts.

Takeaways

• 🛠️ Software Development Lifecycle (SDLC) refers to the process followed to develop, deliver, and maintain software.
• 📋 The first phase is Requirement Gathering and Analysis, where customer needs are collected and analyzed for feasibility.
• 🎨 The second phase is the Design phase, where technical architects create a blueprint based on the requirements.
• 💻 The third phase is Development, where the design is implemented through coding by the development team.
• 🔍 The fourth phase is Testing, where testers ensure that the developed features work as expected in a testing environment.
• 🚀 The fifth phase is Deployment, where the software is moved to production for customer use.
• 🔧 The final phase is Maintenance, where the software is regularly updated and bugs or issues are addressed after deployment.
• 🏗️ SDLC phases remain consistent across different development models (e.g., Waterfall, V-Model, Agile) but vary in timeline and execution.
• ⏱️ Waterfall follows a longer timeline with distinct phases, while Agile involves shorter iterations and frequent releases.
• 📱 Maintenance ensures that software remains functional and up-to-date, handling issues reported by customers post-deployment.

Q & A

What is the Software Development Lifecycle (SDLC)?

The Software Development Lifecycle (SDLC) is the set of processes that a software development team follows to develop, deploy, and maintain software. It encompasses the steps from gathering requirements to maintaining the software after its release.

What is the purpose of the requirement gathering phase in SDLC?

The purpose of the requirement gathering phase is to collect and document all the features and requirements that the customer wants in the software. This information is then used to guide the development of the software.

Why is the analysis phase important in the SDLC?

The analysis phase is important because it involves assessing whether the requirements gathered from the customer are feasible. It includes a feasibility analysis to determine if the technology and resources can meet the requirements.

What happens during the design phase of SDLC?

During the design phase, the technical architects create a blueprint for how the software will be built. This phase is crucial for defining the structure and design of the system, ensuring that it aligns with the customer's requirements.

What is the role of the development phase in SDLC?

The development phase is where the actual coding of the software takes place. The development team uses the design specifications to start building the software by writing the necessary code to implement the gathered requirements.

What is the importance of the testing phase in SDLC?

The testing phase ensures that the developed features work as expected. Testers verify the functionality of the software to identify and fix any issues or bugs before the software is deployed to production.

What does deployment mean in the context of SDLC?

Deployment refers to moving the developed and tested software into the production environment, where the intended users can access and use it. In some cases, deployment may be to a specific set of customers, while in others, it may be made available to the wider public.

Why is the maintenance phase necessary after deployment?

The maintenance phase ensures that the software continues to function properly after deployment. It includes activities like regular updates, fixing any new issues that arise, and ensuring the system remains operational over time.

How does SDLC differ between the Waterfall and Agile models?

In the Waterfall model, SDLC phases are followed sequentially, with longer timelines for each phase, often spanning months or even years. In Agile, the same phases exist but are completed in shorter iterations (2-4 weeks), with frequent updates and continuous delivery of features.

What is the relationship between Software Development Lifecycle (SDLC) and Software Testing Lifecycle (STLC)?

The Software Testing Lifecycle (STLC) is a subset of the SDLC. It focuses specifically on the testing activities within the larger development process, ensuring the quality and functionality of the software during the testing phase.

Outlines

00:00

💻 Introduction to Software Development Lifecycle (SDLC)

The video begins with an introduction to the Software Development Lifecycle (SDLC), a systematic process for building and delivering software. The presenter emphasizes that understanding SDLC is crucial for anyone working in software development, especially testers. They highlight how SDLC applies to different approaches like the waterfall model and agile methodologies, such as Scrum. The presenter sets the stage for a deeper dive into SDLC phases and mentions that software testing lifecycle will be discussed in a future tutorial.

05:00

📋 Requirement Gathering and Analysis

The first phase of SDLC is requirement gathering and analysis. This phase involves collecting and documenting the customer's needs. The presenter uses the example of a company, ABC, receiving a project to build an app. The process involves gathering all the necessary features and documenting them in a requirement document (waterfall model) or user stories/epics (agile). The analysis phase includes feasibility checks, ensuring that the gathered requirements are technically achievable. If certain requirements are infeasible, this is communicated back to the customer for revision.

10:02

🖊 Design Phase: Laying the Foundation

The design phase comes after gathering and analyzing requirements. In this phase, technical architects design the software structure based on the requirements. Using an analogy of building a house, the presenter explains how the design lays out the blueprint of the software before coding begins. The customer must approve the design to ensure it aligns with their expectations. The phase is divided into high-level and low-level designs, covering the overall structure and detailed specifics of the system.

👨‍💻 Development Phase: Building the Software

The development phase, also known as the coding phase, is where the actual software development takes place. Once the design is ready, developers start writing code based on the agreed-upon structure. This phase is compared to building a house after the design and foundation are in place. Developers use the design blueprint to implement the requirements, translating them into functional features.

🔍 Testing Phase: Verifying the Software

In the testing phase, the software is tested by testers to ensure that it meets the defined requirements. The developed features are deployed in a testing environment, and the testing team verifies that the software works as expected. This phase ensures that the software is functioning correctly before it is released to the customer or moved to production. Testers play a crucial role in validating the functionality and identifying any defects.

🚀 Deployment Phase: Delivering the Software

The deployment phase involves moving the software from the testing environment to the production environment. This makes the software available to the customer or end-users. The presenter gives the example of Gmail, explaining how deployment ensures that the software is accessible to users globally. Deployment marks the official release of the software for customer use, ensuring that it is fully functional in the live environment.

🔧 Maintenance Phase: Keeping the Software Running

The final phase of SDLC is maintenance, which involves regular updates and fixes after the software has been deployed. Like servicing a car, software needs to be maintained to ensure smooth functionality. Any issues that arise in the production environment are addressed in this phase. Maintenance also includes bug fixes and performance improvements, ensuring that the software continues to meet the user’s needs over time.

📅 Applying SDLC Across Development Models

The presenter concludes by noting that the SDLC phases remain consistent across different software development models, including waterfall, V-model, and agile. The primary difference lies in the timelines. For instance, in agile, the phases occur in shorter, iterative cycles, whereas, in the waterfall model, they are carried out over longer periods. Regardless of the methodology, understanding the SDLC is crucial for any software development or testing professional.

Keywords

💡Software Development Life Cycle (SDLC)

The SDLC is a structured process followed by software development teams to build, deploy, and maintain software. It covers the entire journey from gathering requirements to maintaining the software post-deployment. This is the central theme of the video, explaining each phase in detail, like requirement gathering, design, and testing.

💡Requirement Gathering

This is the first phase of the SDLC, where the organization collects detailed information from the customer about what they want the software to do. The video describes how requirements are documented, whether through traditional methods like lengthy documents (waterfall) or user stories (agile).

💡Waterfall Development Approach

A traditional software development model where phases of the SDLC are executed sequentially. The video contrasts this with agile approaches, explaining that in the waterfall approach, each phase is completed before moving to the next, making it less flexible for changes.

💡Agile Development Approach

A flexible software development methodology where the SDLC phases are carried out in short, iterative cycles called sprints. In the video, it’s contrasted with the waterfall approach, showing how agile allows for quicker delivery, with regular feedback and adaptation.

💡Design Phase

After gathering and analyzing the requirements, the design phase involves planning the architecture and structure of the software. The video compares this phase to designing a house, explaining that the design ensures all features and components are in place before development starts.

💡Development Phase

The development phase is where actual coding takes place based on the designs. This is where developers create the functionality as per the gathered requirements. The video highlights that development is like building a house once the design is finalized.

💡Testing Phase

Once the software is developed, it undergoes the testing phase to ensure it works as expected. Testers identify bugs and verify that the software meets the customer's requirements. The video emphasizes that testing is crucial before moving the software to production.

💡Deployment

The deployment phase is where the software is moved to production, making it available for the customer or end users. The video uses the example of Gmail being accessible to the public after deployment, emphasizing the importance of this phase in delivering the final product.

💡Maintenance Phase

After the software is deployed, ongoing maintenance is required to fix bugs, update features, and ensure smooth operation. The video compares it to servicing a car regularly to avoid issues, highlighting the ongoing support needed after deployment.

💡Feasibility Analysis

During the requirement analysis phase, feasibility analysis assesses whether the desired features can be implemented based on technological, financial, or operational constraints. The video explains that if certain requirements aren't feasible, they must be communicated to the customer for adjustment.

Highlights

Introduction to Software Development Life Cycle (SDLC) as a structured process for developing and delivering software.

Importance of understanding SDLC for software testing teams, as testing is a crucial part of the development process.

Overview of different software development approaches like Waterfall, V-model, and Agile and how SDLC applies to them.

First phase of SDLC: Requirement gathering and analysis – the process of gathering customer requirements and assessing feasibility.

Importance of documenting requirements and the difference between traditional requirements documentation in Waterfall and user stories/epics in Agile.

Second phase of SDLC: Design phase – involves technical architects creating high-level and low-level designs based on customer requirements.

Emphasis on the importance of verifying the design with the customer to ensure it meets expectations.

Third phase of SDLC: Development – the coding phase where the actual software is built based on the design.

Fourth phase of SDLC: Testing – testing the developed features in a test environment to ensure they meet the requirements.

Fifth phase of SDLC: Deployment – moving the tested code to production, making it available to the customers or end users.

Sixth phase of SDLC: Maintenance – involves regular maintenance and handling any issues reported by customers after deployment.

Key difference between Waterfall and Agile approaches is the timeline, with Waterfall having longer cycles and Agile operating in shorter iterations.

Agile focuses on delivering software incrementally with smaller, more frequent releases compared to the longer release cycles in Waterfall.

In Agile, design, development, and testing occur in short iterations, typically lasting 2-4 weeks.

Conclusion: Understanding SDLC is crucial for anyone working in software development or testing, as it forms the foundation of delivering quality software.

Transcripts

hello everyone welcome again in this

software testing tutorial

we are going to understand what is

software development lifecycle

or sdlc so software development

life cycle is the setup process that

you follow if you're working in any

software development team

to basically start developing the

software and deliver it

until the software is deployed and

maintained right

so the whole process is known as

software development lifecycle

now that process you need to understand

step by step what all phases are there

to develop any software or analyze the

requirement and then develop the

software and deliver it to the customer

or deploy in the production right so we

need to understand

if we want to work in the software

testing team we need to also understand

what software development life cycle is

and based on different you know

approaches will understand how

software development life cycle you know

is in different software development

approaches say for example waterfall

development approach how

sdlc is there and then if you are

following the

model how software development lifecycle

is in the viewmodel or in the agile

approach for example strong so let's

start with the software development

lifecycle

um so here i'll totally cover sdlc

and in the next tutorial i'll cover

software testing lifecycle which is sort

of

a subset of software development

lifecycle sdnc

fits within software development live

site

so the first phase in software

development lifecycle is

the requirement gathering okay so

requirement

gathering

and analysis

okay so what does the requirement

gathering means right so we'll

understand first requirement gathering

and then analysis so say for example

there is an organization uh abc

and this is the organization which takes

the software development project okay so

you will be you know having certain

teams there development teams

so team one two three and these

teams basically work on different

development projects

now any organization or any person

who is the customer who wants to build

something say for example

i am a customer and i want to build an

app

okay so what i'll do is i'll either if

i'm a big organization i'll

you know have a tendering and then i'll

announce that i want to build something

like this there will be multiple

organizations that will build and then

based on those bids i'll choose

the organization or the team that i want

to

give the project right so uh

now if i want to build an app or a

website

uh in the simplest form okay so

i'll provide some requirements to the

organization right so what

requirement gathering is basically once

this abc organization gets the project

and if i am the customer

then i will provide the requirements or

you know there will be team of people

basically in the customer

you know team so who will

provide the requirement to the

organization who wants to

build the software right or who will be

building the software for us

so those requirement when gathered by

this particular organization is known as

requirement gathering

okay so all the features that i want to

be in my app or in my website i will

provide those details and then

all the details will be documented okay

so all the details will be documented

and this is what the requirements

document is

in the waterfall approach this was a

lindy you know requirements document

but in agile it's in the form of user

stories or epics basically so epic will

be the high level user story

that is what captures the high level

requirement of the customer

okay so this is what a requirement

gathering

phase is when you gather the requirement

about the software what customer is

actually looking for

in or in terms of feature what the

customer is looking for into

the software or the app that you're

trying to build

then the analysis phase is basically

once you gather the requirement you also

analyze the requirement whether those

requirements are feasible or not

right so feasibility analysis is very

important so

once the customer provides a certain

requirement there might be some

limitations in terms of technology

support or any other

you know issues because of that

you might not be able to fulfill those

requirements or not be

able to implement those requirements so

in that particular case

what you need to do is you need to

basically analyze and understand that

whether those requirement implementation

is possible or not

if not you need to communicate that to

the customer about

the analysis and then there will be

discussion and

updates accordingly to the requirement

okay so this is about the requirement

gathering and analysis phase this is the

first phase of software development life

cycle

the next phase is the design phase all

right

what this design phase is all about so

once the requirement

are available in the design phase what

the technical architects do

is in the team you have the requirement

and based on those requirements you want

to basically

lay the foundation of how the software

will be built

right so say for example you want to

build a house okay

so the first thing you do is you design

how you want to build

right you don't directly start building

the house without

having a design and understanding how

the house will look like

so if a customer said that i want you

know three rooms in my house two

bathrooms

um you know two kitchen living room

so all those things need to be designed

properly

first and shown to the customer and uh

clarified from the customer

is this how you want to you know um is

this where you want your room to be

is this where you want your kitchen to

be right so same

is true with the software you need to

basically

first design based on what you have got

gathered as the requirement

and then analyze with the customer the

design that that's what exactly he's

want he wants

or she wants so similar is the case like

the car case

so i have the car a customer asked to

you know build a car with four wheels

and i have put four wheels here

right so this is not fit for you so i

need to basically have the design and

show it to customer whether you want

wheels here or whether you want wheels

here right so customer will say no no

this is not what i want

this car is not going to move right so i

want a car that moves so this is how you

clarify the requirement with the

customer

okay so in the design you design how the

overall

software is going to you know what the

design will look like

so technical architects do it and then

this is what the design

phases and in design there are different

phases

as well so high level design low level

design um

that is within the design phase

so that's the second phase third phase

is develop

now what happens in develop is

so development the development phase is

actually the coding phase

right so once you have the design ready

and you know what you are

going to build then you start the

development work or you start building

the house right so you have the design

you have the foundation laid

and then you know you start

putting the bricks and same is the case

with the

software so once the design is ready the

next phase is the development of coding

phase wherein the development team will

start

writing the code to implement those

requirements

okay the fourth phase is the

test okay so once the development is

done

and a development team has you know

created certain features or developed

certain features they will

provide those features or they'll deploy

those features

into the test environment for the

testers

to test okay now if you're you will be

working as a test

uh tester within team you will go to

that particular you know test

environment and

launch the application or the app and

verify

that whatever features or whatever

requirements are being built in this

particular release

they are working as expected right so

this is the

testing phase so in testing phase you do

the testing work for the

application or the app okay

then after the testing

is successful everything is fine and

stakeholders have agreed

to release the software the next phase

is

to basically deploy right

what does deployment so deploy means

deploying to production

so you won't be having all the code into

the testing right you have to basically

move it to production where the customer

can access or if it is for the public

user for example

gmail is the application which is used

by everyone right

all the public whoever has the gmail

account or wants to create a gmail

account

now if gmail google would have developed

and

just kept it there in their testing

environment and not available

over the internet then that's just

within their organization it's not

available to the public

now if it wants the the

customer for gmail are the people like

you and me

right so they have to move it to the

production over the internet

and this is what deployment is so in the

deployment they move the code to the

production

and make it available to the relevant

customer for

whom that software is being built so in

in gmail case it is for

us and that is why it is you know

deployed in the data centers

or the whole code and it is available

over the internet for us to

access the gmail emails all right so in

the deployment phase the actual code is

being deployed

for the customers who are going to use

it

it might be a set of customers or it

might be the wider public

all right so it depends what the context

is of that particular

software so after the deployment phase

the next phase is the maintenance

all right so in maintenance phase

once the deployment happens okay in the

production

the software needs to be maintained

right so for example you

buy a car you bring it it's a new car

after every six months you have to

service it right so it is required

because if you want to use

the car without any issues you have to

basically

take care of it you have to maintain and

you have to see that there are no issues

or there are there are every every

functionality or machinery is working as

expected

similarly in software you have to

basically ensure that you do that

maintenance or regular maintenance

um uh for the software so that it is

not it doesn't crash so say for example

the software

uh might try to do you know hardware

issues or

there might be you know issues within

the software itself so as we have

already understood about the seven

principles of software testing

so 100 testing is not possible and even

though

if you still can't find any more issues

in your software

it doesn't mean that the software that

deployed

that is deployed in the production is

100 defectory right

so you can't say that so in maintenance

phase what happens is you basically

regularly maintain the software

and you also fix any of the production

issues that come through right so once

the software is in the maintenance

you keep a watch on

what all issues are being reported by

the customers

and if there are critical issues or any

issues that are being reported by the

customer they

are being fixed and redeployed in the

production so this is what what happens

into the

maintenance phase right so these

are the key six uh so basically six

phases of software development life

cycle

and you need to understand the software

development life cycle

before you understand the software

testing life cycle

in the next tutorial that i'll cover

right so requirement gathering and

analysis

design development testing deploy and

maintenance very simple

it's a phase or a life cycle that

any development team will follow to

develop any software or application

right now these phases

this is uh you know will remain

true for waterfall for v model for an

even for agile right so in

agile uh you know you will have the

requirement gathering so this

is this won't happen in each and every

sprint but it will happen in you know

say for example two to three months or

in in a one

increment of program increment so there

will be requirement gathering phase

and then design development testing

testing will happen

design development testing happens in

very short iterations two to four week

cycle

but phases are still same so phases will

still be there

the only difference which happens

between these development approaches

is the timeline that you follow in

waterfall approach

it will be longer timelines in a child

it will be smaller timelines

in agile maintenance you know like

deployment

and maintenance or deployment to

production uh can happen every month

okay so it depends how the organization

wants to deploy to the production

okay but in waterfall it was usually

like six months to one year so it

depended

uh how the organization wants to deploy

the production waterfall approach

right so this is the basic software

development lifecycle

um understand it very well

if there are any doubts please comment

in the comment section

and i'll clarify all those doubts so

that you are good enough

to go ahead and explain it to any

interviewer

in the software testing interview so

that's all for this tutorial

please do share and subscribe and thank

you very much for watching