How to Design Your Test Data for Different Testing Types?

Jan 16, 2018

Introduction:

In software testing life cycle, there are several elements that play a major role in testing basic as well as major features and qualities of a software. In today’s day and age, when the world strives for perfection, software testing ensures that the product that is being developed is of superior quality and performs exponentially. The importance of testing is immense in Software Development Life Cycle (SDLC) and by implementing it in the initial stage of software development cycle, developers and testers can identify defects and bugs in the software program and resolve them as early as possible. This not only saves the time of software development, but also assists developers and testers in reducing the cost of the whole process.

However, the process of software testing is in itself complicated and diverse and it too involves various testing techniques, methodologies and tools. One important element of software testing is test data design, which makes the process of testing a software possible. It is with the assistance of test data design that a team of testers are able to analyse and identify testing techniques as well as the defects in a software. Hence, to understand the significance of designing test data for different testing types, here is a detailed description of the same.

Test Data and Its Importance:

The documented data that is used to test the software program is known as test data. It is the basic element that defines the condition as well as the environment in which the process of testing is initiated by the team of expert and knowledgeable testers. The main purpose of test data is to test the adequacy of the software application. It can be produced in a focused or systematic way, or by using other less focused approaches.

Moreover, a test data is either produced by a tester or by a program/function that aids a software tester in test execution. These test data, once created can be recorded for reuse in case a similar error or discrepancy occurs in the future again or it can be used once and then forgotten. The significance of test data is extremely high, because if the test data is inadequately designed, then the test inputs will not be able to cover all the possible test scenarios, which will further impact the quality and effectiveness of the software application under test. Furthermore, test data is divided into two categories:

Positive Test Data: This helps a tester in generating expected results. Moreover, it is used in a confirmatory way, typically to verify that a given set of input to a given function produces an expected and desired output.
Negative Test Data: This is the second type of test data that is used in order to test the unhandled, unexpected, exceptional or extreme input conditions. Furthermore, it is mainly done to challenge the ability of the program to check its response to the above stated factors.

Limitations:

To clearly understand each and every feature of a software or its testing technique, it is necessary to gather as much information as possible. This not only assists the developer and tester in gathering all the required and vital details about the software and it testing technique, but will also allow them to use it in making an informed decision regarding the choice of testing technique. From basic definition and features to its advantages and limitations, every detail is vital and carries a lot of prominence. Therefore, here are some limitations of test data that should be considered by testers during software development and testing process.

It is not always possible to produce enough as well as required test data for testing the software program.
The amount of data to be tested is determined or limited by several considerations, such as time, cost and quality.

Defining Test Data Design:

The process of test design in Software Engineering can be defined as the act of creating and writing test suites for testing a software system, program, or application. It is an extremely essential part of software testing cycle, as by designing test data testers can decide and manage the amount of testing required by the software, which further helps in reducing the testing cost, time and efforts. In short, test design involves creating a set of inputs for the given software, which will provide the tester expected results/output. Hence, the idea of test design is to ensure that the system is working effectively in a good condition and is suitable for release.

Another important quality of test design is that it requires the knowledge of various important details of the software, such as, the software and the business area it operates on, the functionality that is being tested, testing techniques as well as the heuristics. Moreover, planning skills needed to schedule the test is also required, in which the focus is on the order of test cases that should be designed according to the effort, time and cost of the process and details about the consequences of the most important and/or risky features.

Benefits of Test Data Designing:

The above mentioned points appropriately reflect the benefits and advantages of test data designing, which is used for testing software applications and systems. However, its benefits are not just limited to the already mentioned points and there are other very significant qualities and features of test data designing that further increases its importance. Hence, the benefits of test data are:

A well designed test data provide efficient testing and it has just the required amount of test cases to test the system.
No extra test time is lost in writing redundant test cases that would unnecessarily consume more time and efforts whenever they are executed.
Additionally, perfectly created test data do not contain any brittle or ambitious test cases, which require unnecessary time and efforts of the tester as well as that require additional amount of funding.

Types of Test Design Techniques:

In software engineering, one can find a vast array of testing types, which cater to various testing needs and demands of testers as well as their clients. Likewise, there are several types of test data designing techniques in the software industry, each of which is suitable for analysing and identifying a particular type of error or discrepancies. However, these variety of designing techniques can be categorized into two major type of test design techniques, which are further discussed below:

Static Test Design: This is the first type of test design techniques that is used in various testing types to test the quality, effectiveness and performance of the software application. Static test design technique refers to software testing that is either executed manually or with the assistance of a testing tool. It is usually carried out during the early stages of Software Development Life Cycle (SDLC) and is useful for testing multiple aspects of the software, including source code, functionality and requirements specifications and design documents and models.

Manual Static Test Design Technique: It consists of various test design techniques that differ in the formality of the process. Some of these techniques are:

Walkthrough.
Informal Review.
Technical Review.
Audit.
Inspection.
Management Review.

Static Test Design Technique Using Tools: With the assistance of tools, the following elements of the software and application are analysed.

Analysis of coding standard using compiler.
Analysis of code metrics.
Analysis of code structure.

Dynamic Test Design: This type of test design technique involves execution of the test object (application) on a compiler and is carried out during the validation process. In this, the input data is fed into the application and then the program is executed. Moreover, in dynamic testing, various variable quantities such as memory usage, response time, CPU usage and overall performance of the software are analysed against the expected output. Moreover, dynamic test design techniques are further classified into three categories which are:

Specification based.
Structure based.
Experience based.

Guidelines for Designing Test Data:

After understanding the importance of test data and test data designing, it is crucial to look at the guidelines for creating/designing test data, which will be used to test the complete functionality of the software application, program, or system. By following these guidelines, a tester can ensure software’s total test coverage as well as make the process of testing easy and convenient. Hence, these guidelines are:

Developing Accurate Test Data: Testers should concentrate on creating test data that is not very long and that should identify bugs in different stages of the application development process. However, it should not exceed the cost and time that will be required in preparing test data and executing tests.
Create Unlawful Data Set Up: Wrong data set format should be created to check the correctness of the data, as it will not be accepted by the system and it will generate an error message. The aim here is to check whether the error message is generated or not.
Boundary Condition Data Set: Recognize the application’s boundary cases to organise data set that will cover the lower as well as the upper boundary conditions.
Make Correct Data Set: To ensure that an application is responding as per its requirements and to know whether the data is correctly saved in the database/file or not, correct data set should be created.
Incorrect Data Set: These should be created to confirm application behaviour for negative values as well as alphanumeric sting inputs.
Large Data Set Creation: Creating large amount of data set is required for performance testing, load testing, stress testing and regression testing.
Black or Default Data: To ensure that correct error messages are generated or not, the test cases should be executed in the black or default data set environment.
Corrupted Data Should Be Checked: Before initiating the process of running the test case on a particular data, the testers should validate that the data is not corrupted and is free of bugs and any other discrepancies.

Conclusion

Software testing is one of the most crucial stages of Software Development Life Cycle (SDLC) and it should be introduced during the early stages of SDLC, as it is time as well as cost effective. Testing is immensely significant for developers and testers, as it validates the quality and functionality of the software program or application, which is the greatest requirement of clients as well as the end users in today’s ever advancing world. With the assistance of testing, software developers can find all the defects, bugs and errors in the software without any hassle and ensure that the end product is safely developed and ready for its release. Similarly, test data plays an important role in executing the test cases as well as designing proper test data, which is a main part of application test environment.

Moreover, complete test data set makes the process of testing easier for testers, as with the assistance of test case design a tester can easily access complete data that is required for testing application as well as for finding any discrepancies, errors, defects and bugs in the software system/ application. In short, if developers want to ensure the performance and quality of their application and software, they should always perform constant testing on their product.