CALCE PHM Maintenance Planning Tool

Latest version of the tool

CALCE has developed a stochastic decision model that determines when scheduled maintenance makes good business sense, i.e., makes possible a business objective such as a balance of cost and availability.  The model enables the optimal interpretation of life consumption monitoring damage accumulation or health monitoring precursor data, and applies to failure events that appear to be random or appear to be clearly caused by defects.

The initial version of the tool focused on modeling and optimizing the cost avoidance associated with the application of PHM to systems. The tool implements a stochastic discrete event simulation applied to single and multi LRU systems where the LRUs can have no PHM structures, fixed interval maintenance, life consumption monitoring, or precursor to failure health monitoring.  The tool can be used to optimize safety margins and prognostic distances for single LRUs and to determine best maintenance strategies for multiple LRU systems. In Spring 2007, the tool was extended to address false positives.  The tool has been used to perform ROI studies on single LRU systems.  The metrics computed by the tool include:

    • Life cycle cost (of a socket or group of sockets)
    • Failures avoided
    • Operational availability

Recently the tool was  enhanced to model PHM implementation costs (non-recurring development costs, recurring costs at the LRU, socket and multi-socket levels, and infrastructure costs.  A revenue model is also being added to provide to differentiate between unscheduled maintenance that occurs before during and after missions.
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