Default Properties for Items that are Linked
As indicated in
Possible Data Links, the calculation data that is brought over for a linked item depends on the link.
• When an event tree branch is linked to a fault tree gate or event, the time independent unreliability calculated for that gate or event is brought over.
• When an item is linked to a FMEA data level, the failure rate for that data level is brought over.
• When an RBD block is linked to an assembly with a specified value for failure rate or MTBF (mean time between failure), the specified value is brought over. However, this value is modified by the duty cycle of the assembly. Additionally, the corrective maintenance restoration distribution of the linked block is exponential, and the mean time of its distribution is the MTTR (mean time to repair) of the linked system tree item.
Before calculating results, a check is performed to see if the data brought over must be updated. Once the latest linked data is available, results are calculated.