HALT Testing – Highly Accelerated Life Test Consulting

HALT (Highly Accelerated Life Testing) is a method of achieving high product reliability.  HALT utilizes a test to fail technique to identify design vulnerabilities and weakness.  It accomplishes this by employing a combination of stressors that may include: temperature , humidity, vibration, and electrical power parameters to precipitate failures. 

It is most commonly used in the development of electro-mechanical and electronic equipment.  These stress severites are incrementally increased to levels significantly beyond those expected to be encountered in a product’s normal life cycle.  It is of value in verifying that the product will meet design specifications and is therefore usually often conducted prior to validation or qualification testing.  The HALT process may however, be employed at any point in the product’s life cycle to enhance reliability.

HALT is used to to define the operating and destruct limits of a design and identify causes of those limits.  After design modification, the test sequence can be repeated to ensure that the cause for failure has been mitigated.  The intensity of the testing may then be increased to repeat to increase those margins.

Advantages of a HALT Program

Achieving high customer satisfaction, avoiding product recalls, minimizing product design modification cycles, and limiting product liability issues are all reasons for initiating a HALT program.  Unlike DVT (Design Verification Testing), which may take many days or months, HALT can drastically reduce testing time while providing crucial data.  This is especially of value towards the end of a product development cycle.

Conducting testing that simulates actual use, while of great value later in product development, can result in many iterations of redesign.  By performing testing at an accelerated pace HALT can identify vulnerable components and design issues early.  This increases the probability of conducting later product testing successfully.

Once a HALT program has been conducted and a product has been released to production, Highly Accelerated Stress Screen (HASS) testing can be performed to ensure that failures caused by faulty components or manufacturing processes are caught before product is shipped.  The HASS parameters are derived from HALT testing but are not driven to a test to fail level.

Accepted Practice in Many Industries

Although originally developed for electronic products, HALT testing is one of the most widely-used accelerated test methods.   It is often used by manufacturers of defense products prior to environmental testing such as MIL-STD-810.  It is also used in the automotive industry and is a part of General Motors standard GMW3172.  In essence it can be found in most markets that demand high reliability in their products.

Requirements for a Highly Accelerated LIfe Testing Program

To perform HALT special consideration must be given to the set of required monitoring equipment.  This equipment should be capable of capturing intermittent failures as well as total failures.  Once a failure has been created the root cause down to the specific component must be identified for the test to add value.  Adequate resources should therefore be allocated to perform in depth troubleshooting and analysis.

Because HALT usually includes vibration stresses as high in frequency as 10 kHz in 6 degrees of freedom, fixtures should be designed that will not introduce nulls or resonances that would distort the vibration frequency response to the item under test.  CVG Strategy can create vibration fixtures for any test requirements.

CVG Strategy Test and Evaluation Expertise

CVG Strategy can help you develop a product profile and generate a HALT Test Plan that will rapidly give you the data you need to verify the design reliability and get your product to market.  CVG Strategy has decades of experience with HALT and HASStesting.  We also have experience in commercial, aerospace, automotive, defense, and EMI/EMC test and evaluation.