Plant and equipment must be assessed to determine the applicability and extent of the various predictive techniques. This will include the identification of critical equipment, common modes and causes of failure, and the use of appropriate condition monitoring and modelling technology.
Formal procedures will be maintained that detail inspection, testing, and condition monitoring frequencies and scopes for all critical equipment.
Condition monitoring will be used where economically viable and based on the suitability of condition monitoring techniques to reliably detect problems prior to failure condition of equipment.
Attention to the specialised nature of the analysis is crucial to effective condition monitoring. Therefore the review and recommendations for action should be done by an appropriately trained and experienced person specialised in this area.
Equipment condition will be trended to predict the onset of equipment failure and allow timely intervention to prevent the failure using preselected equipment condition limits.
The performance of the predictive maintenance program will be defined and includes targets to accurately measure the predictive program performance and capability. Performance measures should include:
- Schedule compliance
- Defects found and eliminated
- Cost savings
- Cost avoidance
- The impact of the predictive effort on business drivers, and
- Successes and failures of the condition monitoring program activity recorded and estimated, which includes estimated worth and cost to support ongoing program evaluation.
The figure demonstrates one type of bearing failure mode and its associated defect symptoms detectable after the initiation of the failure mode. As the defect deteriorates, more symptoms become evident by use of the appropriate condition monitoring techniques. Understanding the failure mode symptom lead time to failure (P-F interval) ensures the right condition monitoring techniques are selected to ensure enough time is available to carry out corrective maintenance. It also provides the basis to selecting the frequency at which the condition monitoring task should be carried out.
