Reliability Growth Projections and Management
An effective reliability growth test planning and management strategy can contribute greatly to your ability to meet desired reliability goals on time and within the project budget. RGA provides exclusive support for several innovative approaches that expand upon traditional reliability growth analysis methods in ways that better represent real-world testing practices and practical applications for reliability growth planning and management.
Using the Crow Extended Model with Failure Mode Classifications
Traditional reliability growth models allow you to analyze data from tests where the improvements are incorporated during the test (test-fix-test). However, in actual practice, fixes may be delayed until after the completion of the test (test-find-test) or you may implement some fixes during the test while delaying others (test-fix-find-test). In addition, there may be some failure modes that management chooses not to address at all for technical, economic or other reasons.
To more realistically represent the reliability growth management strategy that has been followed, the Crow Extended model allows you to classify each failure mode seen during the test:
- A Modes: No corrective action.
- BC Modes: Corrective action was implemented during the test.
- BD Modes: Delayed corrective action will be taken after the test. For these modes, you also can specify "Effectiveness Factors" to indicate how much the failure intensity of each mode will be reduced once the fix has been implemented.
In addition to traditional reliability growth analysis output, this analysis provides some other results and charts that will help you to evaluate the reliability growth management strategy and make projections.
- Projected MTBF (or Failure Intensity) - the reliability growth that will be achieved when the delayed fixes for BD modes have been implemented.
- Growth Potential MTBF (or Failure Intensity) - the maximum achievable reliability growth for the current reliability growth management strategy. If this metric indicates that your goal cannot be achieved with the current level of testing and fixing, you will be able to take the steps necessary to adjust your strategy.
- Average Failure Mode Strategy Pie Chart - breaks down the failure modes based on classification and other factors. For example, this chart shows the estimated percentage of failure modes that still may be discovered with further testing and the percentage of the failure intensity that you still have a chance to remove from the system.
- New in Version 7!Discovery Rate of New BD Failure Modes - at any given time, the rate at which new (unseen) BD failure modes are being discovered.
- New in Version 7!MTBF for New BD Failure Modes - at any given time, the mean time between the discovery of new (unseen) BD failure modes.
