Continuous improvement in predictive maintenance RULE = Remaining useful life estimate It is commonly called the "Remaining Useful Life Estimate" or by the acronmym "RULE". One performance measure of a predictive maintenance program is the spread of the distribution around the mean (i.e. around the RULE). This spread  is quantified by the standard deviation. Conditional MTBF Continuous improvement in the RULE occurs over time as more experience is gathered. Not only is the RULE adjusted, but the spread narrows. Is the well-known MTBF, except that it is measured from the current moment. That is, the moment when one needs to make an on-condition maintenance decision. And narrows further. Improving RULE The RULE improves Increasing confidence Confidence in prediction increases in a measurable way so that it may be reported as a CBM KPI. Conditional Density Function Continuous improvement in predictive maintenance t0 Working age Current time

Conditional Density in EXAKT