LV 124 testing: How to build a traceable test matrix

If you are planning an LV 124 testing program, having the applicable requirements is only the starting point. The real planning work begins when you need to translate those requirements into a test program that defines what is tested, with which samples, under which conditions, and against which acceptance criteria.

That is where a traceable test matrix becomes useful. It connects the applicable requirements with the test methods, sample groups, test sequence, operating modes, functional monitoring, and acceptance criteria needed for execution.

For validation engineers working on automotive electrical component testing, this article explains how to build that matrix and which details should be clarified before testing begins. 

Why LV 124 testing requires a project-specific test matrix

LV 124 is frequently referenced for the validation of automotive electrical and electronic components. But the reference to LV 124 alone does not define the complete test program for a specific component.

The applicable customer-controlled documents and project requirements need to be reviewed carefully. Depending on the program, differences may relate to:

• test sequence,
• sample allocation,
• operating modes and supply conditions,
• functional monitoring,
• conditioning and recovery periods,
• interruptions and test-stop criteria,
• intermediate inspections,
• acceptance criteria, and
• reporting requirements.

This is why a test plan from a previous project should not automatically be reused for a new component. The starting point should be the controlled project documentation, including the applicable revision and any customer-specific additions. 

Start with a clause-by-clause requirement review

Before building the LV 124 test matrix, the applicable requirements need to be identified for the specific component.

A clause-by-clause review can clarify questions such as:

• Which test cases apply?
• Which installation conditions need to be considered?
• Which component state is required?
• Which tests require electrical operation?
• Where is functional monitoring required?
• Which sample group is assigned to each test?
• Which tests need to be performed in sequence?
• Which conditioning or recovery periods apply?
• Which inspections need to be documented?
• What constitutes a pass, failure, interruption, or technical review?

The objective is not simply to create a list of tests. It is to establish which requirements apply to the component and how they need to be translated into the actual validation program. 

What should an LV 124 test matrix include?

A traceable LV 124 test matrix connects every applicable requirement with its planned execution.

Depending on the project, each row of the matrix may identify:

• requirement or clause,
• test method,
• sample group,
• test sequence,
• operating state,
• supply condition,
• monitoring requirement,
• conditioning period,
• inspection requirement,
• acceptance criterion, and
• reporting requirement.

This provides a shared planning basis for the laboratory, customer, development team, and quality team.

More importantly, the matrix creates traceability. Before testing starts, the project team can see which requirement will be evaluated with which samples, under which conditions, and according to which acceptance criteria.

That makes the matrix more than an administrative document. It becomes the technical link between the original requirements and the evidence generated during testing. 

Why test sequence must be visible in the matrix

Test sequence can influence the behavior of an automotive electrical component.

A component that has already undergone temperature cycling, chemical exposure, or another environmental load may respond differently during a subsequent mechanical or functional test. Previous exposure may affect factors such as housing stiffness, seal behavior, connector retention, material properties, adhesive strength, contact resistance, or electronic performance.

Where a specific test sequence is required by the applicable project documentation, that sequence should be maintained unless a documented technical agreement specifies otherwise. 

The test matrix should make the planned order of exposures, inspections, functional checks, and recovery periods visible. This helps prevent individual tests from being treated as isolated activities when the qualification program requires them to be considered as a sequence.

Planning the complete validation program?

Read Automotive electrical component testing: A validation guide and see how mechanical, climatic, chemical, and electrical requirements can be connected within a coordinated qualification program. 

Define operating modes and functional monitoring before testing

Terms such as “powered,” “active,” or “functional” may not provide enough information to execute a test consistently.

Where applicable, the test plan should define the relevant electrical and functional conditions more precisely. These may include:

• supply voltage and current,
• electrical loads,
• communication state,
• inputs and outputs,
• active functions,
• diagnostic state,
• monitoring intervals, and
• interruption limits.

Functional monitoring is particularly important when temporary failures could occur during exposure. A brief communication interruption, unexpected reset, signal deviation, or intermittent contact may no longer be visible when the component is checked after the test.

The monitoring concept should therefore be considered together with the test matrix rather than added after the mechanical or environmental setup has already been defined.

Need more detail on this part of the setup?

Read Functional monitoring during automotive vibration testing to see why operating modes, signals, communication interfaces, limits, and interruption criteria should be defined before exposure begins. 

How does the test matrix fit into the overall validation program?

LV 124 testing is rarely something you plan in isolation. When you are responsible for an automotive electrical component testing program, you may need to coordinate mechanical, climatic, electrical, chemical, and functional loads as part of the overall qualification approach.

For validation engineers and validation managers, the challenge is to keep these requirements connected. Sample groups, test sequences, operating conditions, functional monitoring, inspections, and intermediate evaluations all need to fit together before testing begins.

A traceable test matrix gives you that overview. It can show which sample undergoes a particular environmental sequence, when the component needs to be powered, which functions need to be monitored, when inspections take place, and which acceptance criteria apply after each stage.

This makes it easier for engineering, validation, quality, and laboratory teams to work from the same plan — and to identify open questions before they become issues during test execution. 

Common planning gaps that can be avoided with a test matrix

Many problems encountered during validation are not caused by the test equipment itself. They arise from requirements that were not fully clarified before test execution.

A structured LV 124 test matrix can help identify open questions, such as whether the correct sample group has been assigned, whether a required operating mode has been defined, or whether the monitoring and acceptance criteria are clear enough for the laboratory to execute the test.

Clarifying these points early can reduce the risk of:

• missing an applicable test step,
• assigning the wrong sample group,
• using the wrong component state,
• omitting required monitoring,
• repeating inspections,
• discovering unclear acceptance criteria during execution, or
• repeating tests because of incomplete documentation.

The goal is not to make the matrix as detailed as possible. It is to make the planned validation program clear enough for the applicable requirements to be executed and traced consistently. 

Planning beyond the LV 124 test matrix?

Explore how imat supports automotive electrical component testing, from vibration and mechanical loads to environmental validation and functional testing.

Conclusion: LV 124 testing starts with a traceable plan

If you are preparing an LV 124 testing program, the key planning task is to turn the applicable requirements into a test plan that your team can execute and trace from start to finish. A generic test list cannot provide that level of clarity.

A clause-by-clause review helps you determine what applies to your component. The test matrix then connects those requirements with the relevant samples, test sequence, operating modes, functional monitoring, inspections, and acceptance criteria.

For validation engineers and validation managers, this traceability makes it easier to see whether the program is complete before testing begins — and to identify open questions while there is still time to resolve them.

At imat, we consider the applicable customer-controlled documents together with the component information, installation conditions, operating modes, monitoring requirements, and project schedule when developing the test matrix and test plan. The goal is a validation approach that is technically clear, executable, and traceable from the original requirement to the final test result. 

Planning an LV 124 test program?

If you are preparing an LV 124 validation program, imat can review your requirements and help translate them into a structured, traceable test matrix. An initial discussion can help clarify the applicable requirements, identify open questions, and define the appropriate next steps for your test program.

Contact imat to discuss your LV 124 testing requirements. 

FAQs about LV 124 testing

What information should an LV 124 test matrix include?

An LV 124 test matrix should connect each applicable requirement with the information needed for execution and evaluation. Depending on the project, this may include the test method, sample group, sequence, operating state, supply condition, monitoring requirements, conditioning periods, inspections, acceptance criteria, and reporting requirements.

Can the same LV 124 test matrix be reused for different components?

A previous matrix can provide a reference for planning, but it should not automatically be reused as the technical basis for another component. Applicable requirements may differ by project, component, installation conditions, operating modes, customer requirements, and document revision.

Why do operating modes matter in LV 124 testing?

The component's operating state can influence what a test is intended to demonstrate and which failures can be detected. Where required, the test plan should therefore define supply conditions, active functions, communication states, electrical loads, and functional monitoring rather than simply describing the component as “powered.”

When should the test matrix be reviewed with the testing laboratory?

The matrix should be reviewed before test execution, while open questions about samples, sequence, operating conditions, monitoring, inspections, and acceptance criteria can still be resolved without interrupting the test program.