A proof-of-screen is used to
verify that HASS test limits (derived from HALT) will catch production defects
without damaging good product. Failure to comply with the prescribed criteria can result in code violations, potential legal consequences, and difficulties in obtaining occupancy permits. Here are some key reasons why compliance with these criteria is crucial.
Software Engineering Stack Exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. While this section recommends an “independent” test organization, it is likely that the contractor will handle the testing from test plan generation to test execution as well. Within most organizations, an independent test group will take on this responsibility and this should be permissible as long as the personnel are independent from the developers and designers.
Understanding the Pass/Fail Criteria
The immunity test system controls the length of the dip and switches between 100% and the dip signal to create the momentary drop in voltage. A tapped auto-transformer selects the dip level and an immunity test system controls the selection using an analog feed signal. But issues often turn up for equipment that is connected directly to an AC or DC power supply. For many pieces of equipment that use external AC/DC adaptors that operate down to lower voltages, this test rarely causes issues. The duration of the voltage dip and the depth of the dip vary and are defined in your standard. It helps to ensure that your equipment functions properly (as expected and safely) with power supply fluctuations.
The reason is that the fix was not incorporated in the newer releases – it was effectively lost when the new release was created. Once detected, they can be fixed, or operational procedures changed, to avoid problem conditions. When an error condition or anomalous event occurs or is suspected, a specific test can usually be developed to capture triggering conditions or circumstances and allow the investigation and resolution of the problem. The key is identifying the conditions that allow the test team and the software developer to produce a test case that reliably reproduces the problem.
Pass Fail Criteria
Further, with custom software, it is likely that there will be no track record of previous testing with the new release which will require that the agency be more rigorous in its testing program. In HALT,
temperature and vibration stress conditions are used during product development
to find weak spots in the product design and its planned pass fail criteria fabrication processes. Other test stimuli may include humidity, thermal cycling, burn-in for a
specified period of time, over-voltage, voltage cycling, and anything else that
could logically expose defects. This requires only a few units and a short
testing period to identify the fundamental limits of the technology being used.
When defining operational tests of longer durations (30-90 days), the procurement specification must be realistic about the probability that external forces will impact system operations. For example, outages with leased communications facilities will impact overall system operation but are beyond the control of the contractor. Also, field facilities may be damaged by vehicles causing knock-downs of equipment. It is not realistic to hold a contractor liable for events beyond their control. There will be small maintenance issues that occur, but these need to be put into perspective and dealt with without impacting the operational test program.
Code and Regulatory Compliance
By varying the voltage, you can vary the current in the H-field antenna (the transducer) and therefore set the magnetic field strength (measured in Amps/m). This version of the test is to ensure that your product works properly in the presence of magnetic fields generated by nearby power cabling. The coupling network is usually contained inside an immunity test system along with a decoupling network which helps to protect the power supply or auxiliary equipment.
I suspect a stronger solution involves looking for statistically significant trends and triggering a failure based on a probabilistic metric. There are a number of testing tradeoffs that can have a favorable impact to cost, scheduling or resources required to conduct the overall testing program. The belief that a software bug found, fixed, and cleared by verification testing will stay fixed is not necessarily true. The problem was resolved and testing verified that it had been fixed; yet it magically appears again. There could be a number of reasons; perhaps the problem was not really fixed or perhaps the problem was simply masked by other “fixes” or features. In some cases, a new release has replaced the previous release and somehow, during the development of the new release, the old problem reappeared.
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Review the contractor’s organization chart and determine the degree of independence of the testing group. Avoid the use of “may” and “should” in the requirement statement unless you specifically want to give the provider an option in how that requirement can be met, or give the receiver an acceptance option or an “out.” If something is not desired, try to phrase the requirement to state what is desired. However, this is not an absolute; if the system is not supposed to allow expired passwords to be used, then an explicit “shall” statement with that requirement should be included. For example, “The system shall reject and log each user logon attempt that uses an expired password.”
- This typically results from a version control problem (or software configuration management lapse).
- The above examples are very simplistic and only apply to a single item.
- If it were, the design should have included a means for avoiding or detecting the problem and taking some corrective action.
- List down all required software and make sure you procure the required software on time so you can proceed with the testing process as per schedule.
- There will be small maintenance issues that occur, but these need to be put into perspective and dealt with without impacting the operational test program.
- Using test design specification, you can simplify understanding of the current testing cycles.
Non-compliance with the prescribed criteria may result in increased insurance costs or even denial of coverage. Building code officials, architects, and engineers rely on the results of an ASTM E119 fire test to verify compliance with fire safety standards and make informed decisions regarding the design and construction of fire-resistant buildings. One of many types of fire testing standards, this test measures the ability of a construction material — such as a wall, partition, roof, or floor — to withstand exposure to fire for a specified period of time.
10 Issues Affecting System Reliability
The ASTM E119 fire test is a standardized test method used to evaluate the fire resistance of building components and assemblies. It is conducted in accordance with the ASTM E119 or UL 263 (Underwriters Laboratories) standard. Next time you make a test plan document, do not forget to include the top 10 attributes in your test plan document. If you know of other important attributes that should be included in a test plan, share them in the comments below. First part is the introduction which provides a brief overview of the project background, scope, testing objectives and references.
In subsequent installation testing with the new release, the old problem resurfaced. The subject fix will now have to be incorporated into a new release and re-tested. If one cannot tolerate the loss or interruption of a critical function (even for a short interval), some form of active redundancy is required. That is, some alternate means of accomplishing the critical function must be instantly available. Several levels of redundancy might be required to reduce the probability of a loss or interruption to near zero.
The operational limit of a product, beyond which it is not required
to function properly. The parameters measured with any of
these HALT/HASS profiles can be any number of signals that indicate whether or
not the product is functioning properly. The measured signals may range from DC
values to high-frequency RF variables.