Calculations and Task Packaging
Even when you choose to use the predefined decision logic diagrams employed by traditional RCM methods, those guidelines still require the analysis team to utilize their knowledge of the equipment's failure behavior when making decisions about the appropriate maintenance strategy. RCM++ provides built-in simulation and calculation engines to help with these assessments.
Choose from a Variety of Statistical Distributions to Describe the Failure Behavior
When you use an MTBF or failure rate to describe the equipment's failure behavior, you are assuming that failures occur at a constant rate regardless of the age of the equipment (i.e. an exponential distribution). Other statistical distributions are more appropriate for situations where the failure behavior varies with time, as in the case of infant morality or wearout. RCM++ allows you to more accurately describe the probability of failure by providing a choice of ten distributions (including, but not limited to, the lognormal, exponential and all forms of the Weibull distribution). Integration with ReliaSoft's Weibull++® and ALTA® software packages makes it possible to obtain the failure time distribution and parameters from an existing data analysis file and the software also provides a utility to help you estimate the distribution parameters based on limited information.
Comparing Maintenance Strategies Based on Cost and Availability
When a failure mode does not involve hazardous consequences that require a conservative prevention strategy, the analysis team may wish to choose the maintenance approach that will provide adequate availability with the lowest operational costs. RCM++ makes it possible to simulate the operation of the equipment with different potential maintenance strategies in order to estimate the expected failures for each scenario and calculate the Average Availability, Cost per Uptime and Total Operating Cost. Calculations are available for the following strategies:
- Run to Failure (i.e. corrective maintenance only)
- Repair/Replacement
- On Condition Inspection
- Service
- Failure Finding Inspection
- One Time Task (e.g. up-front design change)
You can also export system configuration, reliability and failure mode data to ReliaSoft's BlockSim® software for more detailed system modeling and analysis using either reliability block diagrams (RBDs) or fault trees.
Calculate the Optimum Replacement Interval
There are two requirements that must be met for preventive replacement of an item to be worthwhile: The reliability must get worse with time and the cost of the planned preventive replacement must be less than the cost of unplanned corrective maintenance. When both of these requirements are met, RCM++ provides a utility to automatically calculate the optimum replacement interval that will minimize the corrective and preventive maintenance costs.
Task Packaging
RCM++ makes it easy to group individual tasks into packages based on factors such as interval or labor crew. You can manually assign a task to the appropriate maintenance package or allow the software to automatically group tasks based on the criteria that you have specified for each package.
