Manufacturing variation can introduce weaknesses after a product’s design has been evaluated. A component substitution, assembly issue, or process change may affect performance without producing an obvious visual defect. HASS testing helps manufacturers investigate this concern before shipment. Short for highly accelerated stress screening, HASS applies a defined environmental stress profile to production units.
The Applied Technical Services Family of Companies (ATS FoC) provides HASS testing services within our environmental testing and analysis capabilities. We work with clients to develop screening approaches that reflect their product, available HALT findings, and production objectives.
When Should Manufacturers Consider HASS Testing?
HASS can be useful when a manufacturer needs a production screen for latent defects. These weaknesses may remain hidden during a routine functional check and appear only after environmental exposure.
Potential concerns include marginal connections, assembly variation, and defects associated with supplied components. The defects a screen can detect depend on its design and monitoring methods. Manufacturers may consider HASS when:
- Introducing a product into production
- Investigating recurring early failures
- Reviewing a supplier or process change
- Establishing screening requirements for contract manufacturing
- Evaluating the consistency of production hardware
Electronics, aerospace, automotive, and medical device manufacturers may use HASS within broader quality programs. Screening should complement investigation and process control. Finding a defective unit does not explain why the defect occurred or prevent its recurrence. ATS performs HALT testing in our ISO/IEC 17025:2017-accredited, ISO 9001:2015-registered testing laboratories.
How Is a HASS Profile Established?
A HASS profile defines the environmental exposure applied during screening. It may combine temperature changes and vibration with functional checks. Development begins with an understanding of the design’s capabilities. HALT results help establish operating and destructive limits that inform the proposed screen.
However, selecting settings below a destructive limit is not enough by itself. The profile also needs evaluation for effectiveness and its effect on acceptable products. Important planning considerations include:
- The current hardware and software configuration
- Known defects and relevant failure history
- Temperature and vibration exposure
- Fixture arrangement and chamber loading
- Functional monitoring and rejection criteria
- Screening duration and repeat exposure
We review the available information with your team before establishing the project scope. Missing design-limit data may indicate a need for additional development testing.
Can HASS Testing Damage Acceptable Products?
An unsuitable screen can damage hardware or consume an unacceptable portion of its useful life. HASS development must address that risk. Proof-of-screen evaluation examines whether the proposed profile can reveal targeted defects while avoiding unacceptable effects on conforming units. This evaluation is central to establishing a suitable production screen.
A profile should therefore undergo review before routine use. Significant changes to the product or screening setup may also require reassessment. The objective is controlled defect detection. More severe exposure does not automatically produce a better screen, and chamber completion alone does not establish screening effectiveness.
What Information Should You Provide to ATS?
Bring us your existing HALT results, product requirements, production concerns, and available sample information. Details about previous failures can help define what the screen should detect. We also discuss monitoring needs, acceptance criteria, and reporting expectations. Clear requirements support consistent interpretation of results and disposition of screened units.
Contact Us
Contact ATS to discuss your product history and screening needs by calling +1 (888) 287-5227 or submitting a request form on this page. Our HASS services help manufacturers gather information for production quality decisions, and our dedicated customer service team is here to make scheduling quick and easy.
