Software Testing Techniques assist you in creating more effective test cases. Manual Testing Techniques help decrease the number of test cases to be performed while expanding test coverage because exhaustive testing is not possible. They aid in the identification of test conditions that would otherwise be difficult to recognise.
It is also simpler for QA specialists who are familiar with test design techniques to build productive test suites. We get instructions on what to test and how to interpret test conditions by using a specific technique. To put it another way, each test design technique aids in the conversion of available data into useful test cases. In this article, you’ll learn about five popular test design strategies that will help you ensure optimum test coverage while also reducing the amount of time you spend on testing.
Test Design and why do we need it?
Test design is a phase in the quality assurance process in which we develop test scenarios and highlight the framework of the project’s testing activities. A
QA team decides on the best way to increase test coverage with the least amount of effort. The primary goal of the test design process is to shape QA routines so that it is easier to identify requirement coverage. We require test design in order to: develop tests that aid in the detection of critical mistakes; take an insightful tool for testing in order to avoid wasting resources and reduce the number of tests needed to determine the product.
Common Test Design Techniques in Software Testing
You can use a variety of test design techniques, but let’s look at the most popular ones:
1. Boundary Value Analysis
Boundary value analysis is a form of testing that takes place at the intersections of partitions. Maximum, minimum, within or outside limits, typical values, and error values are all included. The boundaries of the defined input values, rather than the centre, are where a large number of errors take place. It’s also known as BVA, and it provides a collection of test cases that put bounding variables to the test.
Equivalence partitioning is complemented by this black box checking methodology. This software testing methodology is based on the idea that if a device performs well for certain specific values, it will perform equally well for all values in the range between the two boundary values.
Framework for Boundary Value analysis
- If an input state is limited to values x and y, the test cases should include both x and y values as well as values above and below x and y.
- If an input state has a large number of values, a test case that exercises the minimum and maximum values should be developed. Values across each minimum and maximum values are also checked in this section.
- Apply the first and second criteria to the production conditions. It produces an output that represents the predicted minimum and maximum values. It also checks for values that are below or over a certain threshold.
Example:
Input condition is valid between 1 to 10
- Less or 0 (invalid)
- 1 to 10 (valid)
- 11 to 19 (invalid)
- 20 to 30 (valid)
- 31 or more (invalid)
Boundary value 0,1,2 and 9,10,11
2. Equivalence Class Partitioning
Equivalent Class Partitioning divides a collection of test conditions into a partition that should be treated the same. This method of software testing divides a program’s input domain into data classes from which test cases are created. The idea behind this method is that a test case for a representative value of each class is the same as a test for some other value of the same class. It enables you to distinguish between true and invalid equivalence groups.
Example:
Input Conditions are valid between 1 to 10 and 20 to 30.
Therefore, there are five equivalence classes:
You select a value from each class, i.e.
-2, 3, 5, 25, 45
3. Decision Table Based Testing
A Cause-Effect table is another name for a decision table. For functionality that responds to a combination of inputs or events, this software testing technique is used. If the user has completed all necessary fields, for example, a submit button should be available. The first step is to define functionalities whose performance is dependent on a number of different inputs. If the input set of combinations is huge, break it down into smaller subsets to make handling a decision table easier.
Create a table for each function and list all possible combinations of inputs and outputs. This aids in the detection of a disease that the tester may have missed.
The steps for making a decision table are as follows:
- Make a list of the inputs in rows.
- Fill in the blanks in the column with all of the rules.
- Fill the table with various input combinations.
- Note the output against the input combination in the last row.
Example:
The submit button in a contact form is only activated when the end user has completed all of the required fields.
| Rule 1 | Rule 2 | Rule 3 | Rule 4 | Rule 5 | Rule 6 | Rule 7 | Rule 8 | |
| Input | ||||||||
| Name | F | T | F | T | F | T | F | T |
| F | F | T | T | F | F | T | T | |
| Message | F | F | F | F | T | T | T | T |
| Output | ||||||||
| Submit | F | F | F | F | F | F | F | T |
4. State Transition
Changes in input conditions change the state of the Application Under Test (AUT) in the State Transition technique. The tester will use this technique to assess the actions of an AUT. This action can be carried out by the tester by sequentially entering different input conditions. In-state transition technique, the testing team uses the state change method to evaluate system actions by providing both positive and negative feedback test values.
Framework for State Transition
- When a testing team is testing an application with a small set of input values, state transformation should be used.
- If the testing team needs to test a series of events that occur in the application under test, this approach should be used.
Example:
In the following example, the user will be able to log in successfully if he or she enters a correct password in each of the first three attempts. The user will be asked to re-enter the password if the user enters an incorrect password on the first or second attempt. When a user mistakenly enters their password for the third time, the action is taken, and the account is blocked.
When the user enters the correct PIN number, he or she is shifted to the Access granted state in this diagram. Based on the diagram above, the following table was created:
STATE TRANSITION TABLE
| Correct PIN | Incorrect PIN | |
| 1. Start | S5 | S2 |
| 2. 1st Attempt | S5 | S3 |
| 3. 2nd Attempt | S5 | S4 |
| 4. 3rd Attempt | S5 | S6 |
| 5. Access Granted | – | – |
| 6. Account Blocked | – | – |
5. Error Guessing
Error guessing is a software testing technique that involves guessing the error that may exist in the code. The approach is heavily dependent on experience, with research analysts guessing the troublesome aspect of the testing application based on their previous experience. As a result, for better error guessing, test analysts must be professional and experienced. A list of possible errors or error-prone situations is counted using this technique. The tester then creates a test case to expose those flaws. The analyst can use previous experiences to identify the conditions when designing test cases based on this software testing technique.
Frameworks for Error Guessing
- The evaluation should be based on prior research experience with similar applications.
- Awareness of common implementation errors Understanding of the device under evaluation
- Know distressed areas from the past
- Analyze past data and test results
To Sum Up
A well-chosen test design technique aids in the efficient use of QA tools. To ensure the most efficient coverage, QA engineers often need to combine many test design techniques. The best combination is often determined by the project at hand. Some experts make decisions based on intuition, rather than relying heavily on theory. Software testing techniques allow you to create more effective cases. There are five methods that are commonly used.
- Boundary value analysis is a form of testing that takes place at the boundaries of partitions.
- Equivalent Class Partitioning divides a collection of test conditions into a partition that should be treated the same.
- For functions that respond to a combination of inputs or events, the Decision Table software testing technique is used.
- Adjustments in input conditions change the process of the Application Under Test in the State Transition technique (AUT)
- Error guessing is a software testing technique that involves guessing the type of error that could occur in the code.
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