ISTQB FOUNDATION 4.0 | Tutorial 31 | Boundary Value Analysis | Test Techniques | ISTQB Tutorials

Summary

This tutorial delves into the ISTQB Foundation Level certification, focusing on Chapter 4.2: Blackbox Test Techniques, specifically Boundary Value Analysis (BVA). It explains BVA as a technique that tests software inputs at boundary limits, where errors are more likely to occur. The tutorial covers the fundamentals of BVA, including two-point and three-point analysis, and provides formulas for identifying boundary values. It also discusses the importance of understanding requirements for effective BVA application and offers insights into how to approach sample exam questions related to BVA.

Takeaways

• 📘 The tutorial is focused on the ISTQB Foundation level certification, specifically Chapter 4 about Test Analysis and Design.
• 📝 The segment 4.2 discusses Blackbox Test Techniques, with a focus on Boundary Value Analysis (BVA).
• 🔍 BVA is similar to Equivalence Partitioning but emphasizes testing at the boundaries of defined ranges, where errors are more likely to occur.
• 📈 The technique is requirement-driven and necessitates detailed information about how classifications and partitions are created.
• 🌐 BVA tests strictly on the boundaries, assuming that developers might make mistakes in the boundary conditions of data validation.
• 🔢 An example illustrates testing the boundaries of a range, such as 18 to 30, by testing values just inside and outside this range (17, 18, 30, 31).
• 📉 BVA identifies valid boundary values (inside the valid range) and invalid boundary values (outside the valid range).
• 🔑 There are two types of BVA: two-point analysis, which tests two values on each boundary, and three-point analysis, which tests three values including the boundary itself.
• 📚 The tutorial provides formulas for quickly identifying boundary values without drawing tables: for two-point analysis (lb, lb-1, rb, rb+1) and for three-point analysis (lb, lb-1, lb+1, rb, rb-1, rb+1).
• 📝 The importance of understanding the difference between 'valid collection of boundary values' and 'valid boundary values' is highlighted, with the former including both valid and invalid values and the latter only valid ones.
• 📑 The script includes sample questions to demonstrate how BVA is applied in exam scenarios, emphasizing the need for careful reading and application of the technique.

Q & A

What is the main topic of this tutorial?

The main topic of this tutorial is the ISTQB Foundation Level certification, specifically focusing on Chapter 4, which discusses test analysis and design, and in particular, the boundary value analysis technique.

What is boundary value analysis in the context of software testing?

Boundary value analysis is a black-box testing technique that focuses on testing the boundaries of input ranges. It is based on the assumption that errors are more likely to occur at the boundaries of the input values.

How does boundary value analysis differ from equivalence partitioning?

While equivalence partitioning divides the input data into groups (partitions) and tests one value from each group, boundary value analysis tests values at the boundaries of these partitions. It focuses on the edges of the ranges rather than the ranges themselves.

What are the two types of boundary values mentioned in the script?

The two types of boundary values are valid boundary values, which are within the valid range, and invalid boundary values, which are outside the valid range.

What are the two types of boundary value analysis discussed in the script?

The two types of boundary value analysis discussed are two-point analysis and three-point analysis. Two-point analysis tests two values on each boundary, while three-point analysis tests three values on each boundary.

What is the purpose of using three-point analysis over two-point analysis?

Three-point analysis is used over two-point analysis when dealing with more critical scenarios or requirements to achieve better test coverage and confidence that the system correctly handles boundary conditions.

What are the shortcut formulas for identifying boundary values in two-point analysis?

In two-point analysis, the shortcut formulas for identifying boundary values are lb (lower boundary), lb - 1, rb (upper boundary), and rb + 1.

What are the shortcut formulas for identifying boundary values in three-point analysis?

In three-point analysis, the shortcut formulas for identifying boundary values are lb, lb - 1, lb + 1, rb, rb - 1, and rb + 1.

How many test cases are required for maximum coverage when applying three-point boundary value analysis to a field that accepts ages between 18 and 30 years inclusive?

When applying three-point boundary value analysis to a field with an age range of 18 to 30 years inclusive, a minimum of six test cases is required for maximum coverage.

What is the minimum number of test cases required if a shopping cart requires a minimum order quantity of five and offers a 10% discount for orders of 100 or more?

When applying two-point boundary value analysis to the given scenario, the minimum number of test cases required would be four, focusing on the boundaries of the order quantities (below 5, at 5, at 99, and at 100).

How can you combine equivalence partitioning (EP) with boundary value analysis (BVA) to create a set of valid test cases?

You can combine EP and BVA by first applying each technique independently to identify boundary and equivalence class values. Then, select only the valid values from both techniques to create a comprehensive set of test cases.

Outlines

00:00

📚 Introduction to Boundary Value Analysis

The first paragraph introduces the topic of boundary value analysis (BVA) as part of the ISTQB Foundation level certification tutorial. It explains that BVA is a blackbox testing technique that focuses on testing the boundaries of input ranges, similar to but distinct from equivalence partitioning. The speaker emphasizes the importance of detailed project information for effective BVA. They provide an example illustrating the rationale behind BVA, explaining how developers might make errors at the boundaries of numerical ranges. The concept of valid and invalid boundary values is introduced, along with the two types of BVA: two-point and three-point analysis. The paragraph concludes with an explanation of how to identify valid and invalid boundary values using examples.

05:01

🔍 Techniques and Formulas for Boundary Value Analysis

The second paragraph delves deeper into the specifics of BVA, offering shortcuts and formulas for identifying boundary values in both two-point and three-point analyses. It explains the concept of 'lb' (lower bound) and 'RB' (upper bound) and how to derive test values from these. The paragraph also discusses the importance of understanding the type of BVA required for a given test scenario, as specified in an examination question. It provides examples of sample questions that might be encountered in an exam, demonstrating how to apply BVA to determine the minimum number of test cases needed for maximum coverage. The speaker advises against being influenced by the context of the question and stresses the importance of sticking to the data and requirements provided.

10:01

📝 Applying Boundary Value Analysis to Practical Examples

The third paragraph presents practical examples to illustrate the application of BVA, including a blend of equivalence partitioning (EP) and BVA. It discusses how to identify valid boundary values and valid equivalence class values when both techniques are applied to a given scenario. The examples include a text field for user age, where the input must be between 18 and 30 years, and a shopping cart scenario with minimum order quantities. The paragraph guides the learner through the process of identifying valid and invalid boundary values, emphasizing the importance of selecting only valid values when combining results from both EP and BVA. The speaker concludes by encouraging patience and careful reading of exam questions, offering assistance for any further queries.

Keywords

💡ISTQB Foundation Level Certification

The ISTQB Foundation Level Certification is an internationally recognized qualification for software testers. It validates the fundamental knowledge of software testing principles and practices. In the script, this certification is the overarching theme, as the tutorial is aimed at preparing individuals for this exam, specifically discussing test analysis and design techniques.

💡Test Analysis and Design

Test Analysis and Design refers to the process of examining a system or application to determine the testing strategy and creating test cases. It is a critical phase in the software testing lifecycle. The video script delves into Chapter 4 of the ISTQB syllabus, focusing on this concept and explaining various testing techniques, including boundary value analysis.

💡Blackbox Test Techniques

Blackbox testing is an approach where the tester checks the functionality of an application without any knowledge of its internal workings. The script discusses this in the context of the ISTQB certification, focusing on techniques like boundary value analysis, which is a blackbox method used to test the boundaries of input ranges for a software application.

💡Boundary Value Analysis (BVA)

Boundary Value Analysis is a testing technique used to detect errors at the boundaries of input ranges or data sets. It is based on the assumption that errors are more likely to occur at the edges of a range. The script explains this concept in detail, providing examples and emphasizing its importance in software testing.

💡Equivalence Partitioning

Equivalence Partitioning is another blackbox testing technique that divides the input data of a software component into partitions of equivalent data from which test cases can be derived. The script mentions this technique in comparison to boundary value analysis, noting that while both are driven by ranges, BVA focuses on the boundaries themselves.

💡Valid and Invalid Boundary Values

In the context of boundary value analysis, valid boundary values are those within the acceptable range of input, while invalid boundary values are outside of this range. The script uses these terms to illustrate the selection of test cases that are on the edges of the defined input ranges, which are critical for testing.

💡Two-Point and Three-Point Analysis

These terms refer to variations of boundary value analysis. Two-point analysis involves testing with two values on each boundary, while three-point analysis includes an additional value within the boundary. The script explains that three-point analysis provides a more comprehensive test coverage, especially for critical data sets.

💡Test Cases

Test cases are specific scenarios or sets of conditions under which a software application is tested to determine whether it will perform as expected. The script discusses the creation of test cases using boundary value analysis, emphasizing the minimum number required for maximum coverage.

💡Exhaustive Testing

Exhaustive testing refers to the process of testing all possible inputs to an application. The script mentions that exhaustive testing is not feasible, which is why techniques like boundary value analysis are used to reduce the number of test cases while still ensuring thorough testing.

💡Sample Questions

Sample questions are hypothetical scenarios or problems provided in the script to illustrate how boundary value analysis can be applied in an examination setting. These questions are designed to test the viewer's understanding of the technique and its application to real-world testing scenarios.

💡Critical Scenarios

Critical scenarios refer to situations where data accuracy and testing are of utmost importance due to the potential impact of errors. The script suggests that for such scenarios, a more rigorous approach like three-point analysis may be warranted to ensure robust testing.

Highlights

Introduction to the ISTQB Foundation Level certification tutorial, focusing on Chapter 4 about test analysis and design.

Exploring the 4.2 section on blackbox test techniques, specifically boundary value analysis.

Boundary value analysis is driven by ranges and is similar to equivalence partitioning but focuses on testing boundaries.

Importance of detailed project information for proper classification and partitioning in boundary value analysis.

The rationale behind testing on boundaries due to common errors in range definitions by developers.

Explanation of how to apply boundary value analysis with examples, such as testing age range validation.

The concept of valid and invalid boundary values in the context of boundary value analysis.

Differentiating between two-point and three-point boundary value analysis techniques.

The significance of three-point analysis in critical data scenarios for better test coverage.

Shortcuts for quickly identifying boundary values without drawing tables for two-point and three-point analysis.

Understanding the examination's expectations regarding boundary value analysis and how to answer related questions.

Sample questions to demonstrate the application of boundary value analysis in test case design.

The importance of not being influenced by the context when applying boundary value analysis.

How to identify valid and invalid boundary values using two-point analysis in a shopping cart scenario.

Combining equivalence partitioning with boundary value analysis for comprehensive test case design.

The distinction between valid boundary values and valid equivalence class values in test case selection.

Final insights on boundary value analysis, emphasizing patience and careful reading of examination questions.

Transcripts

Hello friends and greetings for the day

welcome back to another tutorial on

istqb Foundation level certification we

are in chapter 4 talking about test

analysis and design and continuing ahead

with our same segment that is 4.2

blackbox test techniques and as a part

of today's tutorial we'll be talking

about the next technique that is

boundary value

analysis

well to talk about boundary value

analysis of course it's just similar to

that of the equivalence partition and we

have covered much fundamentals right

there in our previous techniques itself

that is it is more driven by the ranges

and uh we take one test from each range

but slightly different when it comes to

boundary value analysis the scenarios

are of course requirement driven so it

is more important that your project must

have detailed information about how the

classifications are done how the uh

partitions are created how to group The

Elements and so on given that this

information is provided to you and asked

to apply boundary value analysis we do

test strictly on the boundaries taking

one quick simple example that why should

I test something on the boundaries

because when you talk about defining a

range a range is always defined by given

expression for example if I have to

limit a value between 18 to 30 then I

write the expression as 18 less than or

equal to X less than or equal to 30 and

that's how I write the expressions for a

field validation now given that this

data validation invites you to write a

number followed by the operator and that

repeats twice so generally the

developers can go wrong in writing a

number wrong or can be going wrong with

writing the operator as wrong and that's

where we believed or created this

technique called as boundary value

analysis that hey mostly when it comes

to numbers the values go wrong on the

bound boundaries so if I test one inside

and one outside on the extreme

boundaries it would just do my job so in

simple words if I have to test a

boundary validation of 18 to 30 as my

valid set of data then I will test 17 18

30 31 if these four values are giving me

appropriate results then I don't have to

test any other value 17 should be

rejected 18 should be accepted 30 should

be accepted and 31 should be rejected if

these four values are giving me the

right results then I don't have to test

any other number to get to the

confidence that this field will accept

only valid inputs in the same context we

will give you some more outline and

detailed understanding of what this

examination is expecting you and

expecting you to answer during the

examination and we will look at some of

the sample questions from there as well

but before that a quick context about

what is boundary value

analysis so boundary value analysis is

basically a technique which tests

extremely on the boundaries as we

understand the defect can lie near the

boundaries as well okay the values in

valid range are called as valid boundary

values whereas the values from invalid

range are called as invalid boundary

values if you look at the example any of

the examples below it certainly shows

you that there are dots representing

inside and outside the ranges so of

course there might be valid or invalid

ranges appropriately defined by the

requirement So based on that you can

pick up that what is my valid value and

what is my invalid value and at the same

time you can also declare them as valid

boundary value or invalid boundary

values also to add here of course

boundary values are of two types we do

talk about two point analysis and

three-point analysis whereas the two

examples which you see at the bottom are

related to twoo and threo itself the two

point certainly talks about taking two

values on each boundary which is the

vertical partition and three-point

analysis uh asks you to type three

values on each boundary however the the

three-point value may not make sense

initially but if you deep dive a

boundary has three positions okay like

inside outside and on the boundary but

technically speaking the organization

said when I say 18 to 30 18 and 30 are

on the boundary so it's okay to take one

more value inside to be more sure and be

double confident that things are

absolutely working fine but that was not

just one reason of course the companies

with critical set of data they try to

check with three values to have a better

coverage on such scenarios so it's not

that twoo analysis or three-point

analysis can be compared and decided

that which one is the best it's just

that if you're dealing with more

critical scenarios more critical

requirements take three point analysis

into consideration and if you're dealing

with non-critical scenarios to reduce

your effort you can just be limited to

two test cases per boundary so in the

case of twoo analysis my values will be

uh lb lb minus one RB rb+ one now these

are your shortcuts which you probably

will not get on internet and this will

save a lot of your time quickly to come

to the answer right so you don't really

have to draw the table but just

recommended that you can always draw the

table to be more sure but even if you

want you can quickly just use these

formulas to get to the right boundary

values so lb lb minus one RB RB + 1 are

the four values which you will get from

the twoo analysis whereas when it comes

to three-point analysis we take lb lb

minus1 lb + 1 RB RB minus1 RB +1 and in

case of two point two point analysis we

will have four values two valid two

invalid the valid ones will be lb and RB

the invalid values will be lb minus1 and

RB + 1 similarly when it comes to

three-point anal Anis the lb lb + one RB

RB minus one which is inside will be my

valid values and lb minus one and RB + 1

will be my invalid values and you'll

have six six values to pick from this

particular technique so the technique

type that is bva type will be specified

in the examination question that which

one you have to pick twoo analysis or

threo analysis now let's quickly look at

some of the sample questions from here

so that you can get some insight that

what could be expected during the

examination so right here on your screen

you find an example it says a text field

in an application accepts input as the

age of the user now pretty much we

understand that age can be any number

which people can live upon and I

certainly cannot do exhaustive testing

here so that's where we are trying to

reduce our test cases but never be

driven by the context because don't

think about okay what about this person

AG what about that person AG what about

senior citizen and sort of thing now you

don't put your input puts into the

context you just have to follow the

statements get to the data draw the

table get the answer okay never get

influenced by the context because

sometime the context are purposefully

written in a way that you get confused

okay so that's one thing here uh the age

of the user will be considered here the

values allowed to be accepted by the

field is between 180 to 30 years

inclusive of both the values so they

will clearly specify whether you have to

include or not but however

mathematically when you say between it

is inclusive of both the values okay

additionally to the question says by

applying three point boundry value

analysis what is the minimum number of

test cases required for maximum coverage

now right here if you look at the

technique very clearly or with the table

what we have on the screen we by default

know that there will be six test cases

required because it is three-point

analysis and uh there are three

partitions of course people live younger

than 18 years and older than 30 years so

we will certainly be taking six test

cases and the Very straightforward the

right answer should be B that is six so

all you have to do is this maybe the

question looks pretty longer but you

have to be very confident with what

exactly is being asked to you and what

could be the right answer there let's

look at the next question here which

makes more sense with different example

now here we taking two point analysis

and the question is read as minimum

quantity to place the order is five now

that's a little tricky question because

we didn't want it to keep you always

very straightforward so taking a little

weird question so that you can even

learn about it so here they say that

this could be a shopping cart and

they're saying minimum order minimum

quantity to place the order is five that

means anything less than five you cannot

place the order now to get additional

10% off you should buy 100 or more

quantity that means 100 or greater than

that both are included okay 100 you

should buy in order to get 10% off so

that's where they just created a

partition in one single line and what

are the partitions you can have a look

yourself okay but before that based on

Boundary value analysis which of the U

given option consists of valid

collection of boundary values using TW

Point analysis so they clearly specified

that you have to use which technique and

at the same time which type of boundary

value analysis two point or thre point

so now another important thing to

remember just like equence partition

that they said valid collection of

boundary values many people pick only

valid data and they say this is invalid

question because there are no right

answers but I told you again in

equivalence partition also valid

collection means all the four values

what you should have or all the six

values for the three point okay but when

you say valid boundary values then it is

only the one which are inside okay so

valid collection means all the values

collection of valid and invalid and

collection right and valid boundary

value that means only the valid ones and

same way if I say invalid boundary value

then it is only the invalid ones so in

this case of course my partitions will

be four or less than that right because

no order can be placed then the second

range where I can place the order

without discount is 5 to 99 because the

discount is applicable only from 100 or

above and then third partition order

without 10% discount so again it's not

like every time you get invalids on both

the sides ranges you can even get ballot

on all the other side right side also

but all we have to do is create a

partition so now my boundary values are

right written on the top of the table

itself that is 4 5 99 and 100 so even if

you draw the table you'll be sure about

the right answer even if you apply the

uh formulas you'll get to the answer so

in this context if you pick up the

options and look at the options sometime

they will be very crazy to take you on a

many go round to get confused but just

be confident that where you are supposed

to be so so the right answer here will

be 4 5 99 and 100 that is option

C okay so let's quickly look at one more

example where we'll be blending both uh

that is EP and bva and that will give

you a final touch on what can be best

expected in the examination so the next

question what we have for you is

question number three and let's look at

this one it says a text field in an

application accepts input as age of the

user here the values allowed to be

accepted by the field is 18 to 30 so

it's exactly the same question what you

had in the first one and uh right here

we are saying by applying EP and two

point boundary value analysis which of

the given option consist of valid

boundary values and valid equivalence

value now the only ask here is that they

want to know only the valid set of

values not the collection but common

from both the techniques so in this case

you should apply both the techniques

independently first and then take what

is valid among them okay okay so in this

if you look at the table I've clearly

applied first of all I created the

partitions you have 17 and Below then 18

to 30 is valid and on the right 31 and

greater is invalid now first I apply two

point boundary value analysis so I got

17 18 30 31 as my boundary values and

then I applied EP which is like taking

one from anywhere in the range anywhere

so except the boundary value so you

should take any other value now on top

of it we need to select only the valid

ones so I insert Circle the valid part

which is 1830 or in for EP any value

between 18 to 30 so in that context if

you look at Option a 17 is invalid so

you should rule it out uh B 18 30 and 25

looks really good C 18 30 31 31 is

invalid and D 19 20 and 31 31 is invalid

again so even if you just start

separating out you'll get to the right

answer that the right answer is B 18 30

and 25 collection of valid boundary

values and valid equivalence class value

okay so put together that was all what I

had for you for the boundary value

analysis I hope you got a very good

understanding of that and make sure that

you have really patience while reading

the question okay these are pneumatic

questions so that's all from this

particular tutorial team should you have

anything else feel free to comment below

I'm always there to address your queries

and answer them well till then keep

learning keep exploring keep

understanding the context thanks for

watching the video team and happy

learning

[Music]