Citation:
Esperon Miguez M, John P, Jennions IK. (2012) Uncertainty of performance requirements for IVHM tools according to business targets. In: PHM Society European Conference 2012, Proceedings of the 1st European Conference of the PHM Society 2012, 3-5 July 2012, Dresden, Germany
Abstract:
Operators and maintainers are faced with the task of
selecting which health monitoring tools are to be acquired or
developed in order to increase the availability and reduce
operational costs of a vehicle. Since these decisions will
affect the strength of the business case, choices must be
based on a cost benefit analysis. The methodology presented
here takes advantage of the historical maintenance data
available for legacy platforms to determine the performance
requirements for diagnostic and prognostic tools to achieve
a certain reduction in maintenance costs and time. The
effect of these tools on the maintenance process is studied
using Event Tree Analysis, from which the equations are
derived. However, many of the parameters included in the
formulas are not constant and tend to vary randomly around
a mean value (e.g.: shipping costs of parts, repair times),
introducing uncertainties in the results. As a consequence
the equations are modified to take into account the variance
of all variables. Additionally, the reliability of the
information generated using diagnostic and prognostic tools
can be affected by multiple characteristics of the fault,
which are never exactly the same, meaning the performance
of these tools might not be constant either. To tackle this
issue, formulas to determine the acceptable variance in the
performance of a health monitoring tool are derived under
the assumption that the variables considered follow
Gaussian distributions. An example of the application of
this methodology using synthetic data is included.