PRISM FAQ


Why should I consider using PRISM as my reliability assessment tool?
PRISM, the new standard for reliability prediction, is based on SRC's extensive reliability data and experience. PRISM includes:

  • New electronic Component Models based on over 1012 hours of field experience data
  • A comprehensive reliability assessment methodology that takes into account processes used in the management, design, manufacturing, test and maintenance of a system
  • Extensive component databases of field reliability data
  • Integration of user test and field data
  • Free Technical and Software Support
  • Free Updates delivered via the web
  • Free training classes to all registered users

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Has PRISM been accepted in industry internationally as a replacement for MIL-HDBK-217?
PRISM, released in March of 2000 has gained wide acceptance in the R & M user community and is viewed as the replacement for MIL-HDBK-217 and 217-type modeling methodologies. It is often difficult to instill change away from methodologies that have been utilized for decades; however the inadequacies that exist within these predecessor methodologies have helped the community embrace PRISM with much enthusiasm. PRISM deviates from traditional reliability prediction methodologies by allowing a user to factor in test data and address system level design and manufacturing processes to refine a system prediction. These factors known to impact field reliability have been previously ignored. In addition, the newly developed PRISM component and system assessment models address not only operational aspects but also non-operational and/or dormant aspects of a part or system. These models based on SRC's most current reliability data will be updated routinely as new data is collected whereby keeping the models and the PRISM approach current with the state-of-the-art. The best testimonial to PRISM acceptance is systems that are currently being analyzed using PRISM. We are aware that the following types of systems are being assessed: satellite systems, airborne systems, automotive systems, radars, computers, transmitter/receivers, fuel cell electronics and down-hole oil drilling electronics to name a few. PRISM has also been specified as the recommended prediction methodology in a multitude of DoD system procurements.

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What failure rate prediction models are included in PRISM?
Predictive models exist for integrated circuits (Hermetic and non-hermetic), diodes, transistors, capacitors, resistors and thyristors. Additionally, a predictive model was incorporated for software, along with a system level model that accounts for non-component variables.

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How do I determine failure rates for components that do not have PRISM models?
The PRISM tool incorporates extensive field reliability databases that can be used to assess the failure rates of components where PRISM predictive models do not exist.
PRISM also allows user input of data. If a user has field experience or test data, this data can be factored into an analysis.

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Can I perform a simple "component based" reliability prediction using PRISM, similar to MIL-HDBK-217 Parts Count Method?
Yes. PRISM component models are initially assigned default parameters through the PRISM software based on the user selected component and environmental category (e.g., ground, airborne, etc.). These defaults were assigned based on a detailed analysis of electrical stress conditions typical of parts in the SRC database along with the identification of typical environmental use conditions for the broad environmental categories found in MIL-HDBK-217, such as "ground fixed". Any of these defaults can then be changed to tailor the model to better fit the users specific situation. Thus, although the models may initially seem complex a user needs no further information to apply them than would be needed to use the MIL-HDBK-217 Parts Count Method (i.e., part type, quantity and environmental category). As more specific design information becomes available appropriate adjustments can easily be made either at the part level, globally across one branch of the system tree structure or globally for the complete system.

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How does PRISM differ from traditional reliability prediction models?
Traditional reliability prediction models have been based on the operating time of the part, and the units were typically failures per million (or billion) operating hours. The SRC models (and the empirical data contained in the PRISM databases) predict the failure rate in units of failures per million calendar hours. This is necessary because it is the common basis for all failure rate contribution terms used in the model (operating, non-operating, cycling, induced). If an equivalent operating failure rate is desired (in units of failures per million operating hours), the failure rate (Failures/106 calendar hours) can be divided by the duty cycle to yields a failure rate in Failures/106operating hours.

Additionally, resulting assembly and system failure rates are modified by process grading factors for the following failure causes; Parts, Design, Manufacturing, System Management, Wear-out, Induced and No Defect Found. These process grades correspond to the degree to which actions have been taken to mitigate the occurrence of system failure due to these failure categories. This grading is accomplished by assessing the processes in a self audit-like fashion. Any or all failure causes can be assessed and graded. If the user chooses not to address a specific failure cause, the model simply reverts to the default "average" value.

PRISM also allows a user to integrate empirical data taken throughout system development and testing. This data is incorporated using Bayesian techniques that apply the appropriate weights for the different data elements.

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I have a mixture of active-parallel and standby redundancy in major subsystems. Can I calculate the MTBCF of these redundant configurations?
No, not at this time. PRISM currently performs only a series calculation. PRISM does however interface with commercially available programs that can perform this function.

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Can I import my Bill of Materials (BOM) into PRISM?
Yes. PRISM users may import system Bill of Materials (BOMs) directly into the PRISM component library or into a system assessment structure.

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Can I electronically include PRISM output reports into my final report?
Yes. PRISM reports may be exported to several different output report formats including the Microsoft Office suite of products.

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How often is PRISM Updated?
PRISM update releases vary by the needs and complexity of change requests that come in from you, the users. Currently, we are in an annual maintenance release process.

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How can I get software maintenance updates?
Maintenance updates are free to registered users. These updates are available via download from a secure location available only to registered users.

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Can I try out PRISM before I purchase it?
Yes, The PRISM Demo is a fully functioning tool without the ability to save, export or create new systems. To download the PRISM Demo, Click Here.

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Is it possible to get the PRISM Demo sent to me?
Yes, if you are unable to download the PRISM demo, please contact the SRC.

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What kind of technical support is available? and How do I get Technical Support?
The technical support staff is ready to assist you when ever you have questions, concerns or comments regarding the software. Please contact them using one of the following methods:

  • Post to the PRISM User's Forum
  • E-mail the PRISM Staff
  • Fax to SRC Software at (315) 337-9932
  • Call between 8AM to 4PM Eastern US Time zone, Monday through Friday
    In the United States: toll-free 1-888-722-8737
    Outside the United States (315) 337-0900
When contacting Technical Support, try to have the answers to these questions available to help them assist you in the most efficient manner possible:
  1. Operating system of the computer on which PRISM resides. (Windows 95, 98, NT, 2000, and XP English or International version, etc.).
  2. The type of processor in the computer (please include the processor speed).
  3. Any problems that occurred during the installation of PRISM.
  4. The version of PRISM being run. Go to the "Help, About" screen in PRISM.
  5. If a problem has been encountered, what are the exact steps that were performed when the problem was encountered? Please list them in order.
  6. If error messages are being received, please annotate them exactly as they appear on the screen.
  7. Provide the title of the PRISM screen for more assistance

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How do I order PRISM?
PRISM can be ordered on-line through this website or you can contact the SRC order department at 1-888-722-8737 (1-888-722-8737) or from outside the United States (315) 337-0900.

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Are site licenses available for PRISM?
Yes. Multi-license discounts for PRISM are as follows:

  • 2-4 seats: 10% discount
  • 5-10 seats: 20% discount
  • 10+ seats: Contact the SRC

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Can the SRC assist us by performing a PRISM analysis?
Yes, the SRC offers turnkey consulting designed to bring a PRISM user up-to-speed quickly and efficiently in the use of the PRISM tool. SRC PRISM experts can perform a reliability assessment on your system and provide:

  • A detailed technical report that serves the dual purpose of providing a complete system reliability assessment as well as illustrating the PRISM analysis process.
  • A copy of the PRISM Software and analysis files.

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