ISO 17359:2011 pdf download.Condition monitoring and diagnostics of machines-General guidelines.
7 ReliabilIty and criticality audit
7.1 Reliability block diagram
It can be useful to produce a simple high-level reliablltty block diagram, including whether the equipment has a series or parallel reliability effect. The use of reliability and availability factors is recommended to improve the targeting of the condition monitoring processes.
Detailed information on poducing reliabibty block diagrams is contained in references in the Bliography.
7.2 Equipment criticality
A criticality assc5sment of all machines is recommended in order to create a prioritized list ot mactunes to be included for not) in the condition monitoring programme. This may be a simple rating system based on factors such as:
cost of machine down-time or lost production costs;
failure rates and mean time to repair;
redundancy;
consequential or secondary damage;
replacement cost of the machine:
— cost of maintenance or spares;
— life-cycle costs;
cost of the monitoring system:
— safety and environmental impact.
One or more of the above factors may be weighted and included In a formula to produce the prioritized list.
The results of this process may be used when selecting methods of monitoring (see Clause 8).
7.3 Failure modes, effects and criticality analysis
It is recommended that a failure modes and effects analysis (FMEA) or failure mode effect and criticality analysis (FMECA) be performed in order to identify expected faults, symptoms and potential parameters to be measured which indicate the presence or occurrence of faults.
The FMEA and FMECA audits produce information on the range of parameters to be measured for particular failure modes. Parameters 10 be considered are generally those which indicate a fault condition, by either an increase or a decrease in the particular or characteristic measured value or by some other change to a characteristic value such as pump or compressor performance curves, reciprocating internal combustion engine pressure-volume performance curves and other efficiency curves.
7.1 Reliability block diagram
It can be useful to produce a simple high-level reliablltty block diagram, including whether the equipment has a series or parallel reliability effect. The use of reliability and availability factors is recommended to improve the targeting of the condition monitoring processes.
Detailed information on poducing reliabibty block diagrams is contained in references in the Bliography.
7.2 Equipment criticality
A criticality assc5sment of all machines is recommended in order to create a prioritized list ot mactunes to be included for not) in the condition monitoring programme. This may be a simple rating system based on factors such as:
cost of machine down-time or lost production costs;
failure rates and mean time to repair;
redundancy;
consequential or secondary damage;
replacement cost of the machine:
— cost of maintenance or spares;
— life-cycle costs;
cost of the monitoring system:
— safety and environmental impact.
One or more of the above factors may be weighted and included In a formula to produce the prioritized list.
The results of this process may be used when selecting methods of monitoring (see Clause 8).
7.3 Failure modes, effects and criticality analysis
It is recommended that a failure modes and effects analysis (FMEA) or failure mode effect and criticality analysis (FMECA) be performed in order to identify expected faults, symptoms and potential parameters to be measured which indicate the presence or occurrence of faults.
The FMEA and FMECA audits produce information on the range of parameters to be measured for particular failure modes. Parameters 10 be considered are generally those which indicate a fault condition, by either an increase or a decrease in the particular or characteristic measured value or by some other change to a characteristic value such as pump or compressor performance curves, reciprocating internal combustion engine pressure-volume performance curves and other efficiency curves.
