Verification vs. Validation: Differences, Benefits and FAQs

By Indeed Editorial Team

Published 10 May 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Testing software systems and programs before client delivery is crucial to identifying errors and determining the required changes. Verification and validation are two essential testing approaches that software development teams deploy, particularly when using the Agile methodology. Learning about both these methods can help you implement them effectively. In this article, we differentiate between verification vs. validation, discuss their benefits and answer some common questions related to them.

Definition of verification vs. validation

Learning about the differences between verification vs. validation can help you distinguish between these two crucial stages of the software development process. The verification process determines the quality of software or code generated. It includes all the activities that can help produce high-quality software, including testing, inspection, design analysis and specification analysis. Verification is an objective process during which the team implements various strategies by referring to documents and manuals. It usually requires no subjective judgement or evaluation to assess the end product. Verification helps ensure that the software achieves its goal without any technical errors or bugs.

The validation process ensures that the software functionality meets the client's requirements and user expectations. Validation usually takes place at the end of the development process. Companies conduct validation to check whether the product or software developed is working as intended. Validation ensures that the data or code is as per set standards and recommendations. It helps reduce any technical defects and ensures the integrity of the development process and code.

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Differences between verification vs. validation

Here are some differences between the process of verification and validation:

Scope

Verification doesn't include the execution of the entire code or program but focuses on different elements and components. Different verification methods include reviews, walkthroughs, inspections and desk checking. Verification includes static testing to assess whether the software or code conforms to the given specifications. Various verification methods are black-box testing, white-box testing and non-functional testing.

Validation consists of the execution of the entire code or program. Validation is dynamic testing to check whether the software meets the requirements of the client and end-user. So, while the goal of the verification process is to check the software architecture and specifications, the validation process aims to test the functionality of the end product.

Occurrence

Verification finds errors during the early stages of product development, and this process usually continues throughout the development lifecycle. All activities in the verification process focus on ensuring high-quality code and scripts. It's a relatively objective process with minimal subjective judgement required for evaluation.

Validation takes place after the verification is complete to identify functional errors. Validation can be more subjective as compared to verification as it involves making specific assessments of how well the system works. It includes activities like modelling, prototyping and user evaluation.

Responsibility

The quality assurance team is responsible for verification. The team usually reads the code, checks its functionality and assesses if the code functions without error. This process is more manual and focuses exclusively on whether the smaller components of code exist and work. The quality assurance team may simply compare the functionality of the code using a checklist given by the client or developed internally to complete the verification process.

The testing team typically validates the software at the end of the development process after all the verification checks take place. Manual and automated processes can help complete the automation process as it involves running the end product to see whether it's complete, functional and usable. In the validation process, several forms of user testing happen through automated processes and checks to identify specific areas where the software doesn't work as expected.

Related: What Does a QA Engineer Do? (And How to Become One)

Benefits of verification

Here are some benefits of verification:

  • Process simplification: Verification makes the process of software development easy and allows a team to create an end product that conforms to set quality standards.

  • Documentation: Verification usually occurs as per comprehensive documents and reports, which creates a knowledge resource that acts as a reference for the team.

  • Error reduction: It helps in reducing the number of errors that may appear during the later stages of development. Verification in the initial development phase can help prevent costly errors.

  • Failure prevention: It helps in reducing the chances of system failures and crashes. Verification helps in developing a product that's functional and usable.

  • Wastage reduction: Verification helps in reducing product returns, wastage of resources and other expenses by ensuring quality control.

Benefits of validation

Here are some benefits of validation:

  • Cost reduction: Validation helps reduce costs for businesses and improves product performance. Validation ensures that the system meets the requirements for its intended use.

  • Quality improvement: A comprehensive validation process can improve the quality of the output for a particular development project. The primary purpose of validation is to ensure accurate system design and implementation.

  • Customer satisfaction: Validation helps in reducing the likelihood of a critical defect and ensures that clients and end-users are happy with the product. It helps make the final enhancements to ensure the satisfaction of clients.

  • Complaint reduction: Validation helps ensure the quality of the products and reduces complaints, launch failures and other problems.

FAQs about verification and validation

Here are the answers to some common questions about verification and validation:

What are the different approaches to verification?

Validation can have the following approaches:

  • Reviews: Reviews are an organised way of examining documents like design specifications, code and requirements specifications to explore defects in the software.

  • Walkthroughs: These are an informal way of evaluating the product, where different teams go through the product and try to identify any errors and other defects.

  • Inspection: This is a formal method of testing and is considered one of the most preferred and common methods for static testing. It happens through the examination of documents by skilled moderators or testers.

What are the different approaches to validation?

Validation can have the following approaches:

  • Internal validation: The internal validation identifies defects by checking inconsistencies in the function and data.

  • External validation: The external validation process uses the real world for referencing and validating the data.

  • Process validation: The process validation method emphasises data processing procedures as it equates data defects with process defects. Process validation efforts aim to detect, measure and correct process defects.

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What are the types of verification?

Here are some different types of verification methods:

  • Static verification: Static verification involves inspection of the code before its execution, which ensures that the software meets some specified requirements.

  • Dynamic verification: Dynamic verification deals with the working behaviour of the software along with the execution of software. It involves assessing the behaviour of the software through the execution of the system or its components.

What are the different types of validation?

Here are some different types of validation methods:

  • Prospective validation: It's one of the most common types of validation, which helps establish documented evidence through process implementation.

  • Retrospective validation: This is useful for procedures, services and process controls in operation that don't have a formally known validation process.

  • Concurrent validation: It helps monitor critical process steps and test the end-product of the current development process.

  • Revalidation: Revalidation includes repeating the initial validation to maintain the validated status of processes and codes. It consists of an investigative review of existing performance data.

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What are the limitations of validation and verification?

The most significant limitation of verification is the cost, as it can be time-consuming. It's also susceptible to errors because of higher reliance on manual checking, which can impact accuracy. Similarly, validation helps identify and fix issues only after they appear, which can increase the timeline and delivery of the project.

What is the meaning of Agile development?

An Agile development process enables developers and programmers to test and evaluate the product throughout the development lifecycle. This includes different aspects, such as integrating code, performing tests and updating the product features or requirements. Verification and validation are critical components of an agile development process, as they give the entire team a better idea of how they can accomplish the project goals and maintain product quality.

Verification helps increase flexibility to update and improve the code, which is essential in an agile environment. Based on the result of the verification checks, the team can continually improve their product or approach to developing it. Similarly, validation tests help establish the functionality of the product and ensure that the team delivers quality products to the client.

What industries use verification and validation?

Several industries other than the IT industry can benefit from verification and validation processes, like:

  • medical and healthcare services

  • food science

  • insurance and finance

  • pharmaceutical

  • architecture and engineering

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