In an engineering project, a product may be manufactured exactly according to drawings, technical specifications, and design requirements, yet still fail to meet what the customer or project actually needs in real-world use. The opposite can also happen: a prototype may perform acceptably in several initial tests, but when compared with the design requirements, it becomes clear that some of the defined specifications have not been met. This distinction leads us to two important concepts in product development: Verification and Validation.
These two terms are widely used in automotive projects and are sometimes both loosely translated as “product approval” or “product testing,” even though they do not serve the same purpose. Verification generally examines whether the output of a stage or a product complies with the requirements and specifications defined for it, while Validation addresses whether the final product or solution is suitable for its intended use and need. The difference may sound simple in one sentence, but in a real vehicle or component project, correctly distinguishing between the two affects how requirements are defined, how testing is planned, how prototypes are built, and how product readiness is determined.
What Is Verification?
Verification can be described as the process of checking whether an output complies with specified requirements. Put simply, Verification asks whether what we have designed or built is what we originally defined in the Requirement, technical specification, drawing, or other engineering documentation.
Suppose the design team has defined a set of specifications for a component: dimensions must remain within a specified range, the material must have certain properties, the component must withstand a defined load, and the attachment points must match the drawing. Verification activities check whether the design output or manufactured product complies with these requirements. Depending on the nature of the Requirement, this may be done through engineering calculations, analysis, design review, inspection, measurement, or testing.
Therefore, Verification does not necessarily mean performing a physical test. If a Requirement can be verified through drawing review, calculation, or a valid analysis, that method may be appropriate for verifying the requirement. The key point is the existence of a clearly defined requirement and evidence showing that the output complies with that requirement.
What Is Validation?
Validation asks a different question: is the product suitable for the intended use and the actual need for which it was developed? Here, simply matching the product to a drawing or Specification is not enough; it must be assessed whether the product meets the expected need and performance under the conditions in which it is intended to be used.
This distinction is especially important in the automotive industry because a vehicle or component ultimately operates in a real environment and interacts with other systems. A component may meet all dimensions specified in the drawing and satisfy its defined technical requirements, yet still create a problem when installed on the vehicle, operated under the intended conditions, or integrated with other components. Validation aims to identify this gap between “what we designed” and “what is actually needed for the intended application.”
For this reason, Validation is generally closer to the intended conditions of use and may include product testing, performance evaluation at the system or vehicle level, the use of specimens with a maturity level appropriate to the evaluation objective, and assessment under conditions defined to represent the intended application. The type of Validation activity depends on the product, development stage, risks, and project requirements, and there is no single fixed method that applies to every project.
What Is the Difference Between Validation and Verification?
One of the most widely used explanations of the difference is that Verification asks “Did we build the product right?” while Validation asks “Did we build the right product?” This phrase is useful for remembering the distinction, but it is not sufficient for an engineering project. In practice, it is necessary to know how and at what stage each Requirement will be demonstrated and what evidence is needed for product acceptance.
| Verification | Validation |
|---|---|
| Focuses on compliance with specified requirements | Focuses on suitability for the intended use and need |
| Main question: Does the output comply with the Specification? | Main question: Does the product meet the intended need? |
| Can be performed through analysis, review, inspection, measurement, or testing | Can include evaluation of the product or system under conditions representative of the intended application |
| Can be performed at different stages of development | Becomes especially important as product maturity increases and the product approaches its intended application |
| The primary reference is the defined requirements and specifications | The primary reference is the intended use and defined product needs |
It is important not to interpret this table as an absolute boundary. In a real project, a single test may provide evidence for Verification while also forming part of the Validation program; what determines the nature of the activity is the evaluation objective and the relevant Requirement, not simply whether a test machine is used or whether the product is installed on a vehicle.
An Automotive Example: Developing a Vehicle Seat
Suppose a new vehicle seat is being developed. The engineering team has defined a set of Requirements for the seat: its dimensions and attachment points must comply with the vehicle Package, adjustment mechanisms must provide specified ranges of movement, the seat structure must meet defined strength requirements, and the product must be compatible with the cabin space and other vehicle components. During Verification, engineers may review drawings, measure prototype dimensions, perform structural analysis, and carry out appropriate tests for Requirements that require physical testing.
As the project progresses, the issue is no longer only whether each individual feature complies with its own Specification. The seat must be installed in the vehicle, interact appropriately with the driver or occupant position, seat belt, cabin space, and other components, and deliver the expected performance under defined usage conditions. This is where Validation becomes more prominent: evaluating whether the developed product, at a level closer to its intended application, actually meets the needs for which it was developed.
This example also highlights another important point: regulatory and standard requirements can form part of the project Requirements in automotive product development. For example, regulations such as UN R17 apply in the area of seat and head-restraint strength, and the corresponding tests can provide evidence for demonstrating compliance with regulatory Requirements. For more information about this test, you can visit TAT’s Vehicle Seat Strength Test – ECE R17 page.
Is Testing the Same as Verification or Validation?
No. Testing is a method for generating evidence and information, and depending on the project objective, it may be used in Verification, Validation, or other engineering activities. One common mistake is to call every test Validation or to assume that once a product has been tested, its Validation process is complete.
Suppose a Requirement specifies that an assembly must withstand a certain force according to a standardized method. Performing the test may be used to verify that Requirement. In another situation, a specimen with an appropriate maturity level may be tested under a set of conditions representative of the intended application to assess whether the product is suitable for its intended use; in that case, the test may form part of Validation. Therefore, the type of equipment or even the name of the test does not determine whether an activity is Verification or Validation; the purpose the test is designed to address is what matters.
This also demonstrates the importance of test planning. If the project team does not know which Requirement or risk each test is intended to cover, many tests may be performed without systematically generating the evidence needed for the final product decision.
When Do Verification and Validation Begin?
One costly mistake is to treat V&V as an activity that belongs only at the end of the project: first complete the design, then build the prototype, and only afterward determine which tests are required. In a structured development process, Verification and Validation planning should begin as Requirements are being developed. When a Requirement is defined, it is useful to determine at the same time how compliance will be demonstrated, what evidence will be required, and at what stage the evaluation will take place.
This approach has an important advantage: before reaching the final prototype, the project team already knows which specimens, equipment, tests, and schedules will be required. If a test requires a specific specimen, Fixture, measurement equipment, or laboratory booking, identifying this only at the end of the project can delay development. On the other hand, some problems can be identified during analysis or early prototype stages without waiting until the final specimen is available.
What Are Design Verification and Design Validation?
When the terms Design Verification and Design Validation are used, the focus is specifically on the product design. Design Verification checks whether the design outputs meet the design input requirements. In other words, does what the engineering team designed comply with the Requirements that were defined for the design?
Design Validation looks at the design from a different perspective and examines whether the product resulting from the design is suitable for the intended needs and use. To perform meaningful Validation, the evaluation conditions and the specimen used should be appropriate for the Validation objective. In the automotive industry, this may mean using specimens with a defined maturity level, installing the component on the relevant vehicle or system, and running scenarios that represent the intended conditions of use.
Are DV and PV the Same as Verification and Validation?
The terms DV and PV are widely used in the automotive industry and, depending on an organization’s development process, may refer to different Verification and Validation stages or activities. In many processes, DV refers to Design Verification and PV to Production Validation, but the exact definitions of these terms, their Gates, and their associated activities can vary between vehicle manufacturers and organizations. For this reason, DV/PV should not be mechanically treated as equivalent to Verification/Validation without considering the development process of the specific project.
In many projects, DV is performed on specimens built to evaluate the design, with the objective of identifying design weaknesses before production. PV is usually conducted closer to production using specimens in which the product, components, or manufacturing process are more representative of production conditions. However, specimen maturity, required tests, acceptance criteria, and decisions at each Gate should be defined according to the development process of the specific project.
What Is DVP&R and How Is It Related to V&V?
In automotive projects, you may encounter the term DVP&R, or Design Verification Plan and Report. This document generally helps structure the planning of Design Verification activities and record their results. Depending on the organization’s process, a DVP&R may include the Requirement or characteristic being evaluated, Verification method, applicable standard or Procedure, number and type of specimens, test conditions, acceptance criteria, timing, and ultimately the result.
The value of a DVP&R is not simply in having a table of tests. A well-structured DVP&R should show why each test is being performed and which Requirement or risk it covers. If a test appears in the plan but it is unclear which requirement its result is intended to verify, the connection between Requirements and Verification evidence will be weak. Conversely, if an important Requirement has no defined Verification method, the project has a gap in its evaluation plan.
How Is a Test Plan Related to Verification and Validation?
A Test Plan is one of the important tools for converting engineering requirements into executable activities. A suitable Test Plan should define what will be tested, the purpose of the test, the required specimen, the applicable standard or method, test conditions, the data to be recorded, and the acceptance criteria. In more complex projects, specimen scheduling, dependencies between tests, and equipment availability also become important.
However, a Test Plan provides the greatest value when it is connected to the Requirements and the overall V&V program. If a list of tests is simply copied from a previous project, it may not fully match the design, risks, or intended application of the new product. For this reason, test planning should begin with an understanding of the product and its requirements, not with selecting laboratory equipment. This is where engineering and test-planning services can create value before the product enters the formal testing stage.
If the Product Design Changes, Must the Tests Be Repeated?
The answer is not always “yes” or “no.” When a product changes after Verification or Validation, the impact of the change should first be assessed. A small change may have no effect on a Requirement or function that was previously evaluated, while another change—even if visually minor—may alter the load path, material, geometry, software, system behavior, or conditions of use and make some previous results no longer reliable.
For this reason, change management is an important part of V&V. After each change, it should be determined which Requirements are affected, which evidence from previous evaluations remains valid, and which activities need to be repeated or supplemented. The decision to Re-Test should also be based on a technical assessment of the change impact and project requirements, rather than simply on the fact that “this component has already been tested once.”
What Is the Role of the Laboratory in Verification and Validation?
A laboratory can provide an important part of the evidence required for V&V by performing defined tests, but the laboratory alone does not replace the product Verification and Validation process. Defining Requirements, determining the intended application, managing risks, and deciding whether the V&V program is sufficient are activities carried out at the project level; the laboratory performs tests according to the defined method, standard, and conditions, and the results can serve as one of the inputs to engineering decision-making.
This distinction is particularly important in standardized testing. Passing a specific test shows how the specimen performed under the conditions of that test and whether it met the relevant criteria, but the result of a single test should not be interpreted—without considering its scope—as complete Validation of the entire product across all applications. Each test answers a specific question, and the V&V program should cover the set of questions needed to make a product decision.
How Can Engineering and Product Validation Services Support a Project?
In many projects, the main challenge is not performing the test itself; the real issue is determining what should be tested, at what stage, using which specimen, and according to which Requirement or standard. If these questions are answered too late, an unsuitable specimen may be built, a necessary test may be omitted from the plan, or a design change may result in part of the testing having to be repeated.
TAT’s Engineering and Consulting Services support activities such as reviewing technical and regulatory requirements, test planning, and product validation processes. The purpose of these services is not to replace the manufacturer’s engineering decisions or guarantee test acceptance, but to help structure the project path, identify requirements, and plan the necessary activities before testing begins.
If your project is in the development stage and the requirements, necessary tests, or evaluation path have not yet been fully defined, you can also submit a request and provide initial project information through the TAT Customer Communication and Care System so that it can be reviewed initially by the relevant specialists.
Verification and Validation Complement Each Other; They Do Not Replace Each Other
Verification and Validation ask two different questions about a product, which is why one cannot replace the other. A product may meet all defined Specifications but still be unsuitable for the intended application; likewise, apparently acceptable performance of a specimen under a few limited conditions does not prove that all of its design Requirements have been verified. A reliable development process should address both perspectives: Does the output comply with the defined requirements, and does the final product meet the intended need and application?
In the automotive industry, answering these two questions is usually not the result of a single activity. Requirement Management, analysis and design review, prototyping, measurement, testing, system- or vehicle-level evaluation, change management, and documentation of results work together to generate the evidence needed for decision-making. The earlier and more systematically this path is defined within the project, the lower the likelihood that major problems will only be discovered during the final stages of development or during formal testing.