PERFORMANCE REQUIREMENT VS TEST REQUIREMENT
A very important distinction in AGL specifications, FAT, SAT, and compliance matrices — a performance requirement defines what the equipment or system must achieve, while a test requirement defines how that achievement must be verified. One is the result; the other is the proof.
At a Glance
| Aspect | Performance Requirement | Test Requirement |
|---|---|---|
| Main question | What must it achieve? | How do we verify it? |
| Focus | Result / capability | Verification method |
| Defines | Required performance | Test procedure and acceptance |
| Example | CCR output = 6.6 A | Measure output current under specified conditions |
| Example | Fixture reaches required intensity | Perform photometric test |
| Example | Transformer withstands specified voltage | Apply dielectric withstand test |
| Acceptance | Performance limit | Test method + acceptance criteria |
| Usually appears in | Specification/design | Test procedure/ITP/FAT/SAT |
| Can be verified by | Calculation, inspection, test | Specific test/inspection/measurement |
What It Should Do vs How We Prove It
Performance Requirement
"What should the equipment do?"
Test Requirement
"How will we prove that it does it?"
PERFORMANCE REQUIREMENT
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REQUIRED RESULT
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TEST REQUIREMENT
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VERIFICATION METHOD
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TEST RESULT
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ACCEPT / REJECT
Photometric Intensity Distribution
Performance Requirement
The light shall provide the specified photometric intensity distribution.
Test Requirement
Measure the fixture using a calibrated goniophotometer at the specified operating condition and compare the measured intensity distribution with the specified limits.
Performance:
Required candela distribution
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Test:
Goniophotometric measurement
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Result:
Measured candela distribution
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Acceptance:
Within specified limits
Regulated Output Current
Performance Requirement
CCR shall provide regulated series-circuit output current of the specified nominal value.
Test Requirement
Measure output current at each specified intensity step under the specified input and load conditions.
The first statement tells you what is required. The second tells you how to demonstrate compliance.
Electrical Isolation
Performance Requirement
Transformer shall provide the specified electrical isolation between primary and secondary circuits.
Test Requirement
Apply the specified dielectric withstand voltage for the specified duration and verify that there is no breakdown or flashover.
| Performance | Electrical isolation must be maintained | |
| Test | Dielectric withstand test | |
| Condition | Specified test voltage | |
| Duration | Specified time | |
| Acceptance | No breakdown/flashover | |
Adequate Electrical Isolation
Performance Requirement
Insulation shall provide adequate electrical isolation.
Test Requirement
Measure insulation resistance between specified conductors and earth using the specified test voltage.
PERFORMANCE
Adequate insulation
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TEST
Insulation resistance measurement
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CRITERION
≥ specified minimum
Performance ≠ Necessarily Test
A performance requirement can sometimes be verified by:
- Calculation
- Design review
- Inspection
- Demonstration
- Measurement
- Type test
- Routine test
- FAT
- SAT
For example: "Cable ampacity shall be adequate for the design load." This may initially be verified through engineering calculation, rather than a physical test.
Performance requirement ≠ necessarily test requirement.
What a Good Test Requirement Identifies
A good test requirement normally identifies:
- What is tested
- Test method
- Test equipment
- Test conditions
- Test duration
- Measurement
- Acceptance criterion
- Applicable standard
"Measure insulation resistance between the specified conductors and earth using a calibrated insulation resistance tester at the specified test voltage. The measured value shall meet or exceed the specified minimum acceptance value" is far stronger than simply saying "Insulation resistance shall be tested."
Where the Distinction Is Clearest
FIXTURE │ ▼ Required intensity │ ▼ Required beam distribution │ ▼ Required colour │ ▼ Required angular coverage
GONIOPHOTOMETER │ ▼ Specified mounting │ ▼ Specified electrical input │ ▼ Specified angular increments │ ▼ Measure candela │ ▼ Compare against limits
"Required intensity" is performance. "Measure intensity using a calibrated goniophotometer" is testing.
Performance, Test Method & Acceptance Criterion
There is a third concept that is useful alongside the two:
What must be achieved.
How it is measured.
What measured result is considered acceptable.
| Layer | Example | |
|---|---|---|
| Performance requirement | Fixture shall provide required luminous intensity | |
| Test requirement | Perform goniophotometric measurement | |
| Acceptance criterion | All measured values shall fall within specified limits | |
This three-part structure is excellent for technical specifications.
Performance Requirements → FAT Test Plan
Performance Requirements
- Correct electrical rating
- Required intensity
- Correct colour
- Required beam distribution
- Required environmental performance
- Required mechanical characteristics
FAT Tests
- Visual inspection
- Dimensional inspection
- Electrical test
- Photometric test
- Functional test
- Environmental/type-test evidence review
SPECIFICATION
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Performance requirements
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FAT test plan
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Measured results
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Acceptance criteria
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FAT PASS
Site Performance → Site Verification
At site, the performance requirement may be: the installed runway lighting system shall provide the required visual guidance.
The test/verification could include:
- Fixture location inspection
- Spacing verification
- Alignment verification
- Circuit continuity
- Insulation resistance
- CCR operation
- Control verification
- Field photometry where required
SYSTEM PERFORMANCE
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Required runway lighting
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SITE VERIFICATION
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Electrical + alignment
+ functional + photometric
checks
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SAT ACCEPTANCE
Design Capability vs Individual Unit
Type-Test Performance
Demonstrates that the design/product type can meet the requirement.
Example: LED fixture survives specified environmental testing.
Routine-Test Requirement
Demonstrates that each manufactured unit meets specified routine checks.
Example: Each fixture undergoes insulation and functional testing.
Design capability
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Can this product
design perform?
Manufactured unit
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Does this individual
unit pass?
Design Performance vs Equipment Performance
Equipment
CCR maintains specified output current.
System
AGL circuit provides the required lighting intensity and operational functionality.
EQUIPMENT PERFORMANCE
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CCR / Transformer / Fixture
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SYSTEM PERFORMANCE
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Complete AGL installation
Passing equipment tests does not automatically prove system performance.
One Performance Requirement, Many Test Requirements
Performance requirement: the series circuit shall operate at the specified regulated current and provide the required lighting output.
Possible test requirements:
| Test | What It Verifies | |
|---|---|---|
| CCR output-current test | CCR performance | |
| Continuity test | Circuit integrity | |
| Insulation-resistance test | Electrical insulation | |
| Transformer test | Isolation/electrical performance | |
| Fixture functional test | Light operation | |
| Photometric test | Optical performance | |
| Control test | Switching/control functionality | |
Together, these tests provide evidence for the overall performance requirement.
Good Engineering Practice
| Requirement | Type | Verification Method | Acceptance |
|---|---|---|---|
| Rated voltage | Performance | Electrical measurement | Within specified limits |
| Rated current | Performance | Current measurement | Within specified limits |
| Insulation | Performance | IR test | ≥ specified minimum |
| Dielectric strength | Performance | HV withstand test | No breakdown |
| Photometric intensity | Performance | Goniophotometer | Within specified limits |
| Dimensions | Requirement | Inspection | Within drawing tolerance |
| IP protection | Performance | Applicable IP test | Required IP rating |
| Functional operation | Performance | Functional test | Correct operation |
| Installation alignment | System performance | Field measurement | Within specified tolerance |
Two Traps to Avoid
A statement such as "perform insulation resistance test" doesn't tell you what performance is required.
Performance: Equipment shall provide the specified insulation level. Test: Measure insulation resistance using the specified method. Acceptance: Result shall be ≥ specified minimum.
Not automatically — a test can be performed and still fail.
Test performed ≠ test passed ≠ requirement satisfied. The result must always be compared with the acceptance criterion.
Building It Right
1. Requirement
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2. Performance parameter
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3. Required value / limit
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4. Verification method
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5. Test condition
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6. Acceptance criterion
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7. Test record
Requirement: Isolation transformer shall provide the specified electrical isolation. Performance: Dielectric withstand capability shall meet the specified value. Test: Perform dielectric withstand test at the specified voltage and duration. Acceptance: No breakdown, flashover or unacceptable leakage shall occur.
What? How? Pass/Fail?
Performance — what must the equipment/system achieve?
Test method — how will we verify it?
Acceptance criterion — what result makes it acceptable?
Performance Requirement vs Test Requirement
Performance requirement = required capability/result. Test requirement = method used to verify that capability/result. Acceptance criterion = limit used to decide pass/fail.
The strongest compliance structure is: Requirement → Performance Parameter → Test Method → Test Condition → Acceptance Criterion → Test Result → Compliance Status. That structure works particularly well for AGL fixtures, CCRs, isolation transformers, cables, L-823 connectors, photometry, insulation testing, continuity testing, FAT, SAT and commissioning.
This distinction is critical throughout AGL specifications, FAT, SAT, and compliance matrices — confusing the two produces weak, unenforceable technical requirements.
Engineering & Expert Notes
Write Both in the Specification
SpecificationState what must be achieved and how it will be verified.
Check Acceptance Values
AcceptanceMake sure values and methods are consistent.
Link Each Requirement to a Test
TraceabilityUse a compliance matrix.
Check Editions
CurrencyConfirm versions.
Frequently Asked Questions
A performance requirement defines what the equipment or system must achieve, while a test requirement defines the method used to verify that achievement — one is the result, the other is the proof.
No. A performance requirement can be verified by calculation, design review, inspection, demonstration, measurement, type test, routine test, FAT, or SAT — not necessarily a physical test.
Not automatically. A test can be performed and still fail. Test performed does not equal test passed, and test passed does not equal requirement satisfied unless the result is compared against the specified acceptance criterion.
The acceptance criterion — the specific limit or result that determines whether the measured value from the test is considered acceptable.
A type test demonstrates that a product design can meet the performance requirement, while a routine test demonstrates that each individually manufactured unit meets specified routine checks — both are test requirements, but at different levels.
No. Passing individual equipment tests, such as a CCR output-current test, does not automatically prove that the complete AGL system meets its system-level performance requirement — installation, alignment, and field verification are also needed.
Governing Documents
For an actual project or maintenance program, always verify the current edition of the applicable documents and the approved specification/test procedure.
FAA AC 150/5345-53
Airport Lighting Equipment Certification Program (ALECP) — the FAA framework that formalizes this exact distinction, requiring third-party certifiers to test equipment against each individual specification's performance and acceptance requirements before listing.
FAA AC 150/5345 Series
The individual equipment specifications (fixtures, CCRs, isolation transformers, connectors) that each carry their own performance requirements, test methods, and acceptance criteria.
ICAO Annex 14, Volume I
Aerodrome Design and Operations — performance-based requirements for visual aids, verified through applicable national/project test procedures.
DGCA / AAI Requirements
For Indian airport projects, also verify applicable DGCA requirements, AAI requirements, and approved FAT/SAT test procedures and acceptance criteria.
Final Engineering Note
Every specification requirement should carry a defined performance parameter, verification method, test condition, and acceptance criterion — an ambiguous requirement produces an unenforceable compliance matrix.
A performance requirement without a linked test requirement cannot be verified, and a test requirement without a linked performance requirement proves nothing.
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