Introduction
Design validation (DV) is a testing process that aims to ensure if the design of a product or system is really
working in life, and parallel fulfils the customer needs by meeting the specified requirements (not only on paper!). So basically design validation
means physical testing activities and must be performed on prototypes or concepts. DV is applied in all major industries, and it is highly mandatory
in safety relevant sectors (e.g. automotive, aerospace, etc.). Design validation is also referred to as design and development validation, for example in
ISO 9001. Note: validation is not equal to verification, as verification means
the evaluation whether the product or system has been designed and produced according to the specifications, drawings, regulations, instructions, etc.
Simply said:
- Verification: did I make what I had written down previously?
- Validation: did I make what really works (and what the customer needs)?
During the conduction of design validation tests, the engineers intend to measure the performance of the product,
evaluate its function and simulate the environment of the typical use. The below list contains usual test methods of the automotive industry for
mechanical, electrical components, or both:
- Functional and performance testing (e.g. vehicle road test, active test of electrical assemblies).
- Mechanical tests (e.g. surface hardness test, mechanical shock, vibration test, drop test, test for strength and robustness, etc.).
- Electrical tests and EMC (electromagnetic compatibility) tests.
- Chemical exposure and material tests (e.g. for corrosion).
- Environmental and climate tests (e.g. ADT - Accelerated Durability Testing, ART - Accelerated Reliability Testing, heat-shock, vehicle test,
special life-time testing, Xenon-arc Accelerated Exposure, etc.).
A complete and successful test proves, that the design itself is reliable.
Partial example of Design validation of an electric module in the automotive industry:
| Design Validation test report (example) |
| Product name |
P/N |
Date of test |
Project |
Extended test |
Reason for test
|
| Electronic control unit |
xxx.xxx.xxxx |
10.02.2017 |
New model year 2018 |
Yes |
Testing of B sample prototypes |
| Test sequence |
| Test name |
Period / duration |
Operating conditions (Active / Passive) |
Duration of cycle |
Number of cycles |
Temperature |
Remarks |
| High temp. (artificial ageing) |
96 h |
P |
- |
- |
90C |
- |
| Thermal shock (artificial ageing) |
50 h |
P |
30 min |
100 |
-45oC … +80oC |
Transition time (variation): 15 s |
| High temp. active test |
800 h |
A |
- |
- |
+85oC |
- |
| Active temp. cycles |
400 h |
A |
8 h |
50 |
-45oC … +80oC |
- |
| Test Name |
Period / duration |
Operating conditions (Active / Passive) |
Acceleration |
Number of shocks |
Testing temperature |
Remarks |
| Mechanical shock |
5 ms / shock |
P |
300 m/s2 |
14 |
RT (room temp.) |
- |
| Test Name |
Period / duration |
Operating conditions (Active / Passive) |
Acceleration |
Frequency |
Testing temperature |
Remarks |
| Vibration test (sinusoidal) |
16 h / axis |
A |
25 m/s2 |
50 Hz |
RT (room temp.) |
- |
Source: qMindset.com
Key Features
Design validation is a key part of the automotive
APQP
framework’s "Product and Process Validation" phase. In APQP, the "Production validation testing" is and engineering test, which validates if the product
meets engineering standards and specifications. That means DV test must be performed, finished and evaluated before product launch. On top of that,
engineers in the automotive or aerospace industry, start design validation tests already on the first prototypes (e.g. A, B samples), before the design
freeze. This is very important on those products, that are considered as high-tech, or using totally new technologies.
Not only the APQP manual, but also
ISO/TS 16949
and
IATF 16949 request DV test to be finished prior to the delivery, and the analysis
of field reports for previously designed, similar products. Maintaining test documents and records is also mandatory.
Source: qMindset.com; AIAG APQP Manual; ISO/TS 16949
Hints
It is very important to note that design validation is not equal to design verification. Both are mandatory
elements in quality and project management, however the intention is different.
- Validation: a physical test of the product that validates, if the design of the product / system itself is capable of meeting design
requirements.
- Verification: an exercise on paper that checks if the design is developed according to, and complies with standards, governmental
regulations, industry-specific regulations, customer requirements. In addition it analyses if the design outputs met the design input
requirements.
Source: qMindset.com
