About Evaluating Results of a Reliability Growth Analysis

The following list gives a brief description of the graphs that display the data:

• Cumulative <Measurement> plot: Displays the number of measurements recorded for the Asset as a function of time. Since the log (cumulative measurement) versus the log (cumulative time) is linear, the plot line is a straight line. You can use this plot to see how your data is trending over time.

• Mean Time Between <Measurement> Trend plot: Reflects how frequently measurements are being recorded for pieces of equipment or locations (e.g., failures, cost) as a function of time (cumulative operating time). If the trend in this plot is:

  • Increasing, measurements are being recorded less often (e.g., if a measurement is taken every time the Asset fails, the Asset is failing less often). This indicates that the Asset is becoming more reliable.
  • Decreasing, measurements are being recorded more frequently (e.g., if a measurement is taken every time the Asset fails, the piece of Asset is failing more often). This indicates that the Asset is becoming less reliable.
• <Measurement> Rate Trend plot: Reflects the rate of your measurements (e.g., failures, cost). This plot can tell you a measurement per time unit, so that you can see per day or per month when measurements increase or decrease.

The following list gives a brief description of the values calculated by the GE Digital APM system that you can use to interpret trends within your data:

• Goodness of Fit: Helps you determine if the measurements are following a pattern or occurring at random.
• Confidence: Indicates the percentage of uncertainty of the Goodness of Fit method. The confidence level you select for your data helps determine whether or not the data will pass the Goodness of Fit test.
• The Beta Value: Helps you interpret the MTB<Measurement> Trend plot. This value is displayed on the Reliability Growth page.
• Next Estimated Event Date: Provides an estimate of the amount of time you can expect to pass before the next event will occur for the piece of equipment or location. The value is calculated using the last datapoint and the MTBF or measurement rate. The approximate date (or time) when the next event will occur is displayed on the Reliability Growth page.
• Initial and Final MTBF or Initial or Final <Measurement> Rate: Helps you compare how the piece of equipment or location is behaving at the beginning of the analysis versus the end of the analysis. Using these values, you can determine if the piece of equipment's or location's measurement rate has improved or deteriorated over the analysis period. These values are displayed on the Reliability Growth page.

Additionally, you can view the AMSAA Reliability Growth Model page for an overview of the formulas used by the GE Digital APM system to calculate the model results.

The following tools can further assist you in interpreting and applying analysis results:

• Splitting an analysis: Allows you to divide an analysis into multiple parts so that you can see multiple trends in the data (e.g., data before and after a strategy change).
• Extrapolation: Allows you to estimate the number of measurements (e.g., failures, amount of cost) that will have occurred by some point in the future.

Based on the analysis results, you can generate recommendations for the maintenance and reliability activities that should be executed in the future to maintain best practices in your organization.