Implementing best software testing strategies is a crucial part of software development, ensuring that digital products meet industry standards. Defined by the International Software Testing Qualification Board, it encompasses a range of activities, both static and dynamic, throughout the software’s lifecycle. As an essential component of the Software Development Life Cycle (SDLC), the Software Testing Life Cycle (STLC) follows a structured approach to uphold quality. In this informative blog, we will understand various types and strategies of software testing, exploring its significance, goals, methodologies, and impact on modern software development and performance improvement.

What is Software Testing?

According to the International Software Testing Qualification Board; Testing is a process consisting of life cycle activities, both Static and Dynamic types of software testing that includes planning, preparation, and evaluation of software and related products (websites and applications) to determine that they satisfy specified requirements; to demonstrate that they are fit for purpose and to detect defects. Software Testing Life Cycle (STLC) is a chronological specific steps-based testing process and a subset of the Software Development cycle; executed to ensure that quality goals are met (these steps are itself a part of various software testing strategies). It includes:

• Process: Testing is a set of different software testing life cycle activities. In this stage you focus on various strategies of software testing.
• Planning, Preparation and Evaluation: These are broad stages of the Software Testing Lifecycle.  In this, planning refers to planning the test (Requirement Analysis and Test Planning). Preparation refers to designing the test and setting up its environment (Test Case Design and Test Environment Setup). At last, execution is the phase of testing (Test Execution and Test Cycle Closure).
• Satisfy Requirements, Demonstrate and Detection: To determine that software will satisfy the requirements of users and clients, demonstration to check that it is ready to launch and to debug the errors (Detection).

Why is Software Testing a crucial aspect?

Incorporating effective software testing strategies plays a vital role in the Software Testing Development Life Cycle (SDLC). Its major objectives are as follows:

• Bug detection and future repeated prevention: It is the most vital principle of Software Testing that includes functional, requirement, and usability defects. These bugs should be archived such that they can be easily preventable in the future. 
• Security, Usability and Performance: Bug Testing not only makes software bug-free but also allows other benefits like Security, Usability, and better Performance for the website or application. For example: Testing such that a site can handle sensitive credit card details securely (when tested to be highly secure), a Web page is content enriched but high search time to give results (need testing on performance improvement). 
• Reduction in cost: Software Testing directly prevents reputation and reliability costs. For example: Suppose MakemyTrip accidentally books a ticket for 1st January even when the customer chose 31st December. Imagine the reliability and brand cost that the company suffers due to such bugs. 
• Increase in customer satisfaction: Software Testing plays a crucial role in maintaining and enhancing customer satisfaction which ultimately leads to higher organization reliability and revenue growth. For example: Amazon today is the world’s largest E-commerce website which grabbed $ 523.26 Bn in 2022 singly from its website traffic.
• Assures highest standards or as per client need of software quality: Software Testing is a quality double-check on producing what the client desires. 
• Self-improvement: Self-improvement is one of the aspects seen in Software Testing where continuous testing happens to improve the Testing process in order to achieve good end results. For example: Mobile applications regularly come up with updates for “Minor Bug Fixes” which happen due to Continuous Testing done on the application.

Check out our other blog: Software Testing Evolution: From Manual to Automated Testing

What are the strategies used in performing Software Testing?

There are 100+ different types of testing which doesn’t mean testing features on Mobile, Web or Tabs. These are the same irrespective of wherever we are Testing although it varies with the purpose of websites. For example: The Testing done for E-Commerce websites is different from that done for Insurance Policy Websites. For  Each type of testing has:

• Specific Objective: Why are we doing that particular testing?
• Proper Stage Of Implementation: When will we do that testing?
• Actor For Testing: Software Tester, Beta Tester.

Software Testing Types Based On Classification

Testing can be of several types. Popular classifications are as follows: 

• Based on the type of technique: Static Testing (Inspection Testing, Review Testing, and Walk-through Testing) and Dynamic Testing (also includes Stage-based Testing i.e. Functional and Non-Functional).
• Based on the stages: Functional Testing (Unit Testing, Integration Testing, System Testing, Smoke Testing, Sanity Testing, Regression Testing, Re-testing, Acceptance Testing) and Non-Functional Testing (Performance Testing, Security Testing, Usability Testing, Compliance Testing)
• Based on the actors (UAT): Alpha, Beta, A/B Testing, etc.

Testing Strategies Based on Types of Techniques

Let’s understand the types and strategies of software testing based on their technique:

1. Static Testing

It is a non-executing, reviewing, and verification technique used for testing even before the execution of code. Under this, requirements and quality should be correct and code coverage should be good. It can be done by:

• Looking at code and verifying them (non-executing).
• Looking at requirement documents and verifying them (reviewing).
• Looking at design documents and verifying them (verification).

Static Testing can be further classified into different types and strategies of software testing as

1. Inspection Testing: Under this, a formal review of documents happens and test cases are checked with the help of the MODERATOR; who organizes the meeting. A checklist is prepared that is reviewed formally and the scriber writes all the necessary changes.

2. Review Testing: It can be technical or formal 

• Under Technical Review; the Development Manager checks for specifications and checks whether coding standards are met or not.
• Under Informal Review; informal comments and feedback by all colleagues are documented which are to be reviewed.  

3. Walk-Through Testing: Under this; the owner (Project Manager) explains the product and the participant listens and asks doubts and queries. Scribe notes are done; to document and discuss it later.

     2. Dynamic Testing

It is a code executing, functional, and non-functional behavioral testing done by developers and testers inclusively. Functional behavior includes providing an Input, recording Output, and Comparing it with the expected results whereas non-functional behavior is the Performance, Usability, and Security of the system. 

For example: Checking the policy premium for different age groups on a policy website is a Functional Testing type whereas checking its website loading time, and handling card details at the payment interface is Non-Functional Testing. 

Various types of Dynamic Testing are White Box Testing and Black Box Testing:

1. White-Box Testing: Under this; the developers go inside the system up to the code level to check whether all code statements are covered, checking flaws in loops and covering code paths. Therefore, the execution of things is done through code. 

2. Black-Box Testing: It is the most common process used by Testers or Developers; where without going into the system/inner details; we give input and check the output. It can be a (i) Functional or (ii) Non-Functional Testing type. In this; the internal system structure is not known.

One Line Difference: White Box Testing (WBT) includes what software is supposed to do and how it does whereas Black Box Testing (BBT) includes what software is supposed to do but not how it does. 

For example: While doing a Test Drive for a car; the Buyer only focuses on how it is working. The basic intricacy regarding the working of the IC engine, Suspensions, Braking system, etc. doesn’t matter to him. Hence, Buyer’s Testing is a type of Black-Box Testing. 

(i) Functional Testing

Functional testing is yet another essential component of software testing strategies. It is used to verify or check that a system (application or web) should function as per requirement by using the Black-Box technique (one of the components of software testing strategies). 

Various types of Functional Testing are as:

1. Unit Testing: It is a type of Functional Testing done on a single/unit module. Such testing is done by Software Developers at an individual level to check the distinct syntax and responses.
2. Integration Testing: It is a type of Functional Testing that occurs for the interface between two modules after their joining. For example: Validate the log-in and mailbox’s module interface link.
3. System Testing: It is the stage of most exhaustive testing done by a specialized Testing team. This type of testing includes Smoke Testing, Sanity Testing, Re-Testing, Regression Testing, etc. 

• Smoke Testing:  It is a quick testing done on the build to verify the stability of the system (done by Developers).
• Sanity Testing: Such type of testing is performed on a daily basis to verify new features and specialized checks. For example: Testing the functionality of added new products on any E-commerce website.
• Regression Testing: It is used to verify a recent change that shouldn’t affect existing functionality. Hence, it is a comprehensive type of Functional Testing. For example: Verify the email ID login on Facebook after adding the feature of logging the ID with a mobile number.  
• Re-testing: This is a type of testing used to verify the test cases that failed earlier. E.g.: Failure to add a product in a Cart for an E-commerce website, OTP failure in the mobile app. The flow-chart that describes the flow of Functionality Testing is as follows:

Smoke Test —> Sanity Test —> Re-Test —> Regression Test

• Acceptance Testing: This is done by end-users to verify that the website or software should perform as per user convenience. Under this, the testers will be in the ‘user’s hat’ to check the functionality.

(ii) Non-Functional Testing: 

This testing verifies Non-Functional features of a system (web page or application) like performance, security, instability, etc. 

Various types of Non-Functional Testing are as:

• Performance Testing: This type of testing is done to verify website or application performance. There are 50+ different types of Performance Testing itself. The most widely used are Load and Stress Testing. Load Testing verifies system response time to a specified number of users. For example: Check the landing page loading time with different batches of users. Stress Testing verifies system response time by giving more load than designed. For example: Check the landing page response time with more than designed active users on a website.
• Security Testing: It unleashes vulnerabilities or threats within the system. For e.g.: Handling card details by a UPI app.
• Usability Testing: This type of testing checks how much the system is user-friendly. It is done by User-Acceptance Testing (UAT).
• Compliance Testing: This testing is done to confirm adherence to standards, procedures, and guidelines to any legal authority. For e.g.: Credit Cards should follow PCI compliance.

Testing Types Classified based on User-Acceptance Testing (UAT): 

This type of testing is done by the end-users/ client of the system to check whether the system is as per business requirements and check its acceptability. Various types of software testing under UAT are as follows:

1. Alpha Testing: In Alpha Testing; we call end customers at the Developer’s site to give them feedback, comments, etc. 
2. Beta Testing: It is quite different from Alpha Testing where end-users are at their own locations and then use it; through which we get the user acceptability result.
3. A/B Testing (Split Testing): It includes the creation of two versions of a product to check the effectiveness of any version. For ex.: When the Facebook-like button was introduced; it was deployed to a batch of users only in order to check the responses. When the response was desired; the version was fully released for the rest of the world.   

Conclusion

Software testing is vital for ensuring software meets requirements, is defect-free, and fit for purpose. It involves planning, preparation, and evaluation to verify quality, mitigate risks, and enhance reliability. Key benefits of incorporating strategies of software testing include bug prevention, security, usability, cost reduction, and customer satisfaction. Adopting effective software testing strategies and continuous improvement efforts helps achieve quality goals and long-term success in competitive markets.