Using PHM to Meet Availability-Based
Contracting Requirements
Taoufik Jazouli
Peter Sandborn
“Availability-based” contracting originated because
customers with high availability requirements are in many cases
interested in migrating from buying the actual system to buying
the availability of the system. A well-known example of
availability-based contracting is Performance Based Logistics
(PBL).
Prognostics and Health Management (PHM) methods are incorporated into systems to avoid unanticipated failures that can
potentially impact system safety, result in additional life cycle cost, and/or adversely affect the system availability. While
predicting the availability of a system based on known or
predicted system parameters is relatively straightforward and
can be accomplished using existing methods; determining the
system parameters that result in a desired availability is not and
is generally performed using “brute force” search-based methods
that become quickly impractical for designing systems with more
than a few variables and when uncertainties are present.
This paper presents the application of PHM within a “design for
availability” approach that uses an availability requirement to
predict the required logistics, design (including reliability) and
operation parameters with and without the application of PHM
methods. A life cycle cost analysis is used to quantify trade-offs of
using PHM methods versus more traditional maintenance
approaches in the context of availability contracts.