PDCA Cycle in Software Testing: A Continuous Improvement Approach

Learn how the PDCA (Plan-Do-Check-Act) cycle drives continuous improvement in software testing. This guide covers testing types (black box, white box, gray box), the importance of early test design, and how to integrate testing throughout the software development lifecycle for higher quality.

Software Testing Interview Questions

PDCA Cycle

Question 1: PDCA Cycle in Software Testing

The PDCA (Plan-Do-Check-Act) cycle is a continuous improvement model. In software testing:

  1. Plan: Define testing goals and strategy.
  2. Do: Execute the tests.
  3. Check: Analyze test results.
  4. Act: Implement improvements based on findings.

Testing Types: Black Box, White Box, and Gray Box

Question 2: Black Box, White Box, and Gray Box Testing

Testing approaches:

Testing Type Description Knowledge Required
Black Box Tests functionality without knowledge of internal implementation. Requirements specifications
White Box Tests functionality using knowledge of internal implementation. Source code
Gray Box Tests functionality with some knowledge of internal implementation (limited). Partial knowledge of internal design/implementation

Early Test Design

Question 3: Advantages of Early Test Design

Designing tests early helps identify defects early, saving time and resources. It ensures that testing is incorporated from the start rather than as an afterthought.

Types of Defects

Question 4: Types of Defects

Common defect types:

  • Wrong: Incorrect implementation of requirements.
  • Missing: Requirements not implemented.
  • Extra: Functionality not specified in requirements.

Exploratory Testing

Question 5: Exploratory Testing

Exploratory testing involves simultaneously designing and executing tests. It's a flexible, experience-based approach that's effective for finding unexpected issues and often done without creating test cases in advance.

When to Use Exploratory Testing

Question 6: When to Perform Exploratory Testing

Exploratory testing is often used as a final check before release, complementing more structured testing approaches.

Risk-Based Testing

Question 8: Risk-Based Testing

Risk-based testing prioritizes testing efforts based on the potential risk associated with different parts of the system. Higher-risk areas are tested more thoroughly.

Acceptance Testing

Question 9: Acceptance Testing

Acceptance testing verifies that a software product meets the needs and requirements of its end-users and stakeholders. Different types include:

  • User Acceptance Testing (UAT): Testing by end-users.
  • Operational Acceptance Testing: Verifying operational readiness.
  • Contract Acceptance Testing: Ensuring compliance with contractual obligations.
  • Regulation Acceptance Testing: Verifying compliance with regulations.

Accessibility Testing

Question 10: Accessibility Testing

Accessibility testing verifies that a software product is usable by people with disabilities (visual, auditory, motor, cognitive).

Ad Hoc Testing

Question 11: Ad Hoc Testing

Ad hoc testing is informal, unscripted testing. Testers try to find defects by exploring the application randomly based on their experience.

Agile Testing

Question 12: Agile Testing

Agile testing follows agile principles. Testing is integrated throughout the development lifecycle, emphasizing continuous feedback and collaboration.

APIs (Application Programming Interfaces)

Question 13: What is an API?

An API (Application Programming Interface) is a set of rules and specifications for building software that can access services or data from other systems. It defines how different software systems communicate with each other.

Automated Testing

Question 14: Automated Testing

Automated testing uses software tools to execute tests automatically. It's more efficient than manual testing for repetitive tasks and helps improve the speed and accuracy of testing.

Bottom-Up Testing

Question 15: Bottom-Up Testing

Bottom-up testing is an integration testing approach where individual low-level modules are tested first, then combined and tested, continuing until the entire system is tested.

Baseline Testing

Question 16: Baseline Testing

Baseline testing establishes a performance benchmark against which future performance can be measured. This helps in tracking changes and improvements over time.

Benchmark Testing

Question 17: Benchmark Testing

Benchmark testing compares the performance of an application against industry standards or competitor products.

Web Testing

Question 18: Important Testing Types for Web Testing

Important testing types:

  • Performance Testing
  • Security Testing
  • Usability Testing
  • Compatibility Testing

ETL Mapping Sheet

Question 33: ETL Mapping Sheet

An ETL mapping sheet documents how data is transformed during the ETL process, showing how source fields map to target fields and any transformation rules involved. This is used to ensure data integrity.

ETL Transformations

Question 34: Transformations in ETL

Data transformations are operations performed on data during ETL. These include data cleansing, data type conversions, data aggregation, and more.

Dynamic vs. Static Caching

Question 35: Dynamic vs. Static Caching

In ETL:

  • Dynamic Caching: Updates dimension tables periodically.
  • Static Caching: Used for data that doesn't change frequently (e.g., data from flat files).

Data Purging

Question 39: Data Purging

Data purging is the process of permanently deleting data from a database or data warehouse to remove unwanted or obsolete data and reclaim storage space. This is done periodically.

ETL Tools vs. OLAP Tools

Question 40: ETL Tools vs. OLAP Tools

Differences:

Tool Type Focus Examples
ETL Data integration and transformation Informatica, DataStage, etc.
OLAP Data analysis and reporting Business Objects, etc.

Software Testing Life Cycle and Methodologies

Question 1: PDCA Cycle

The PDCA (Plan-Do-Check-Act) cycle is a continuous improvement model. In software testing, it involves:

  1. Plan: Defining testing objectives and creating a test plan.
  2. Do: Executing the test plan.
  3. Check: Analyzing test results and identifying defects.
  4. Act: Fixing defects and improving processes based on test results.

Testing Types

Question 2: White Box, Black Box, and Gray Box Testing

Software testing approaches:

Testing Type Description
Black Box Testing Tests functionality without looking at the internal code structure.
White Box Testing Tests functionality using knowledge of the internal code structure.
Gray Box Testing Tests functionality with partial knowledge of the internal code structure.

Advantages of Early Test Design

Question 3: Advantages of Early Test Design

Designing tests early in the software development lifecycle (SDLC) helps prevent defects, improves overall software quality, reduces costs, and enhances the efficiency of the testing process.

Types of Defects

Question 4: Types of Software Defects

Defect categories:

  • Wrong: Incorrect implementation of a requirement.
  • Missing: A requirement that was not implemented.
  • Extra: Functionality that wasn't required.

Exploratory Testing

Question 5: Exploratory Testing

Exploratory testing involves designing and executing tests simultaneously. Testers use their experience and knowledge to explore the system and find defects.

When to Use Exploratory Testing

Question 6: When to Perform Exploratory Testing

Exploratory testing is often used as a final check before releasing a product to identify any unforeseen issues.

Risk-Based Testing

Question 8: Risk-Based Testing

Risk-based testing prioritizes testing based on the potential risk associated with different parts of the system. Higher-risk areas receive more testing effort.

Acceptance Testing

Question 9: Acceptance Testing

Acceptance testing verifies if a software product meets user and business requirements. Types include user acceptance testing (UAT), operational acceptance testing, contract acceptance testing, and regulation acceptance testing. Alpha and beta testing are often part of the acceptance testing process.

Accessibility Testing

Question 10: Accessibility Testing

Accessibility testing ensures that software is usable by people with disabilities.

Ad Hoc Testing

Question 11: Ad Hoc Testing

Ad hoc testing involves informal, unscripted testing to find defects by exploring the system randomly.

Agile Testing

Question 12: Agile Testing

Agile testing aligns with agile development principles. Testing is integrated throughout the development lifecycle, emphasizing collaboration and continuous feedback.

API Testing

Question 13: API (Application Programming Interface) Testing

API testing is a type of software testing that focuses on the application programming interfaces (APIs) to ensure data exchange and backend functionality. It verifies that APIs meet functional and non-functional requirements.

Web Application vs. Desktop Application Testing

Question 19: Web Application vs. Desktop Application Testing

Differences:

Application Type Testing Considerations
Web Application Load testing, security testing, compatibility across browsers are crucial.
Desktop Application Focus on functionality, usability, and compatibility with the operating system.

Verification vs. Validation

Question 20: Verification vs. Validation

Differences:

Concept Description
Verification Checks if the software is being built correctly (static testing of documents and code).
Validation Checks if the software is built correctly (dynamic testing of the application).

Retesting vs. Regression Testing

Question 21: Retesting vs. Regression Testing

Differences:

Test Type Description
Retesting Re-running tests on a previously failed test case to verify that the defect is fixed.
Regression Testing Verifying that new code changes haven't introduced new defects into existing functionalities.

Preventative vs. Reactive Testing

Question 22: Preventative vs. Reactive Testing

Preventative testing focuses on preventing defects (e.g., code reviews); reactive testing finds defects in the already developed system.

Exit Criteria

Question 23: Exit Criteria

Exit criteria define when a testing phase or level is complete (e.g., all planned tests executed, all critical defects fixed).

Decision Table Testing

Question 24: Decision Table Testing

Decision table testing is used to test systems with complex rules or decision logic. The table lists possible input combinations and the corresponding expected outputs.

Alpha and Beta Testing

Question 25: Alpha and Beta Testing

Differences:

Testing Type Testers Environment
Alpha Testing Internal team Development environment
Beta Testing External users Real-world environment

Random/Monkey Testing

Question 26: Random/Monkey Testing

Random testing involves feeding random input data to an application to identify unexpected behavior or crashes. This helps in identifying unforeseen issues in software or systems.

Negative and Positive Testing

Question 27: Negative and Positive Testing

Negative testing involves providing invalid input to check error handling; positive testing involves providing valid input and checking for the correct output.

Test Independence

Question 28: Test Independence

Test independence helps in reducing bias and improves the objectivity of test results. Independent testers can identify more defects than the developers who created the software.

Boundary Value Analysis

Question 29: Boundary Value Analysis

Boundary value analysis focuses on testing values at the edges of input ranges. This helps find defects at boundary conditions.

Testing the Login Feature

Question 30: Testing the Login Feature of a Web Application

Test cases should cover valid and invalid login attempts, session management, password changes, and logout functionality. The security aspects of login must also be considered.

Types of Performance Testing

Question 31: Types of Performance Testing

Types of performance testing:

  • Load testing: Tests under increasing load.
  • Stress testing: Tests under extreme conditions (resource constraints).
  • Endurance testing: Tests for long durations under load.
  • Spike testing: Tests under sudden changes in load.

Software Testing Life Cycle and Methodologies

Question 1: PDCA Cycle

The PDCA (Plan-Do-Check-Act) cycle is a structured approach to continuous improvement. In software testing, it involves planning tests, executing those tests, analyzing results, and then taking action to address issues and improve processes.

Testing Types

Question 2: White Box, Black Box, and Gray Box Testing

Testing methodologies:

Testing Type Description
Black Box Testing Tests the functionality of the software without knowing the internal code structure or design.
White Box Testing Tests the functionality using knowledge of the internal code structure and design.
Gray Box Testing Combines aspects of both black box and white box testing; involves some level of knowledge of the internal structure but not exhaustive knowledge of the entire system.

Advantages of Early Test Design

Question 3: Advantages of Early Test Design

Designing tests early helps prevent defects, improve software quality, and reduce the overall cost and time needed for testing and fixing defects.

Types of Defects

Question 4: Types of Defects

Software defects can be:

  • Wrong: Incorrectly implemented requirements.
  • Missing: Unimplemented requirements.
  • Extra: Unnecessary or unintended functionality.

Exploratory Testing

Question 5: Exploratory Testing

Exploratory testing involves designing and executing tests simultaneously. It is often used to explore a system's behavior and discover defects not easily found through scripted tests.

When to Perform Exploratory Testing

Question 6: When to Perform Exploratory Testing

Exploratory testing is often a final step before release, used to identify unexpected issues or edge cases.

Risk-Based Testing

Question 8: Risk-Based Testing

Risk-based testing prioritizes testing efforts based on the likelihood and impact of potential risks. Higher-risk areas are tested more thoroughly.

Acceptance Testing

Question 9: Acceptance Testing

Acceptance testing is performed to determine if a product meets user and business requirements. Types:

  • User Acceptance Testing (UAT)
  • Operational Acceptance Testing
  • Contract Acceptance Testing
  • Regulation Acceptance Testing
  • Alpha and Beta Testing

Accessibility Testing

Question 10: Accessibility Testing

Accessibility testing verifies that software is usable by people with disabilities.

Ad Hoc Testing

Question 11: Ad Hoc Testing

Ad hoc testing is unscripted, informal testing. Testers explore the application randomly, trying to find defects.

Agile Testing

Question 12: Agile Testing

Agile testing is an iterative approach where testing is integrated throughout the development lifecycle, aligning with the principles of agile development.

API Testing

Question 13: API Testing

API (Application Programming Interface) testing focuses on verifying the functionality of APIs. It doesn't involve the user interface (UI); instead, it directly tests the data exchange and backend logic.

Performance Testing Types

Question 31: Types of Performance Testing

Types:

  • Load testing: Tests system behavior under increasing load.
  • Stress testing: Tests system behavior under extreme conditions (resource constraints).
  • Endurance testing (Soak testing): Tests for long durations under load (to detect memory leaks).
  • Spike testing: Tests the system's reaction to sudden load changes.
  • Volume testing: Tests system behavior with large amounts of data.
  • Scalability testing: Tests the ability to handle increased user demands and increased volume of data.

Functional vs. Non-functional Testing

Question 32: Functional vs. Non-functional Testing

Differences:

Test Type Focus Examples
Functional Verifying software functionality against requirements. Unit, integration, system, acceptance testing
Non-functional Evaluating non-functional aspects (performance, security, usability). Load, stress, volume, security, usability testing

Static vs. Dynamic Testing

Question 33: Static vs. Dynamic Testing

Differences:

Test Type Description
Static Testing Testing performed without executing the code (e.g., code reviews, inspections).
Dynamic Testing Testing performed by executing the code (e.g., unit testing, integration testing).

Negative vs. Positive Testing

Question 34: Negative vs. Positive Testing

Differences:

Test Type Input Purpose
Positive Testing Valid input Verify correct functionality
Negative Testing Invalid input Verify error handling

Software Development Life Cycle (SDLC) Models

Question 35: SDLC Models

Common SDLC models:

  • Waterfall
  • Spiral
  • Agile
  • Prototype
  • V-Model
  • RAD (Rapid Application Development)
  • RUP (Rational Unified Process)

Smoke, Sanity, and Dry Run Testing

Question 36: Smoke, Sanity, and Dry Run Testing

Differences:

Test Type Description
Smoke Testing High-level testing to verify basic functionality. Usually automated.
Sanity Testing In-depth testing of a specific feature. Usually manual.
Dry Run Testing A walkthrough of a process or code; a mental or manual execution of a sequence without actually running it; used to identify potential issues.

Web Application Testing

Question 37: Web Application Testing

Web application testing includes:

  • Functional testing
  • Integration testing
  • System testing
  • Performance testing
  • Security testing
  • Usability testing
  • Compatibility testing

Compatibility Testing

Question 38: Compatibility Testing

Compatibility testing verifies that an application functions correctly across different browsers, operating systems, devices, and network conditions.

Test Case Creation and Review

Question 39 & 40: Test Cases Per Day

This would involve a discussion on the number of test cases a tester can create and review in a day, which varies depending on experience and task complexity. A reasonable range and its explanation should be provided here.

100% Bug-Free Products

Question 42: 100% Bug-Free Products

It's unrealistic to expect a completely bug-free software product. Testing aims to reduce the number of defects and improve quality, not eliminate all of them.

Bug Tracking

Question 43: Manual and Automated Bug Tracking

Manual bug tracking involves documenting defects; automated bug tracking uses tools (like Jira, Bugzilla) for efficient management.

Causes of Bugs

Question 44: Causes of Bugs

Causes of bugs:

  • Software complexity.
  • Poor coding practices.
  • Requirements miscommunication.
  • Changing requirements.
  • Time pressures.

When to Stop Testing

Question 46: When to Stop Testing

Factors influencing when to stop testing:

  • Meeting pre-defined criteria (e.g., test coverage).
  • Time constraints.
  • Budget limitations.
  • Critical defects resolved.

Test Cases and Testing Types

Question 47: Test Cases and Testing Types

Test cases are typically written for:

  • Functional testing
  • Integration testing
  • System testing
  • Acceptance testing
  • Regression testing
  • Security testing
  • Recovery testing

Other types (like smoke testing, ad hoc testing, usability testing, and compatibility testing) may or may not require formal test cases.

Traceability Matrix vs. Test Case Review

Question 48: Traceability Matrix vs. Test Case Review

Differences:

Activity Purpose
Traceability Matrix Ensures each requirement has associated test cases.
Test Case Review Verifies test cases cover all scenarios.

Use Case vs. Test Case

Question 49: Use Case vs. Test Case

A use case describes user interactions; a test case is a specific test to validate a feature or functionality. Test cases are often derived from use cases and requirements.

Testing a Pen

Question 50: Testing a Pen

This is an open-ended question assessing your ability to think creatively about testing. It aims to explore different testing methods, including functional, usability, performance, and more.