Preventative maintenance of module with failure-prone components

[croseward]

I have set up my RBD in BlockSim so that each subsystem has its own diagram. The MTTF figures are presently unknown for each of the subsystems, so we are extrapolating from the component level. Thus, all MTTF numbers have been input at the component level. In this particular case, if any one component in a subsystem fails, the whole subsystem will be replaced. I would like to have a final block diagram composed of each of the subsystems - with preventative maintenance figures inserted at the subsystem/subdiagram level - but when I get to this point I can no longer access the preventative maintenance options. Is there a way to do this without losing the component level MTTF's?

[Arai.M]

At this point, you have not lost the MTTF of the components as all the properties are inherited from the blocks for that particular subdiagram. However, as you have noticed, you cannot input maintenance that will be common to all blocks at the subdiagram level. You can however define a preventive maintenance policy for each block in that subdiagram based on group item. What this means is that whenever a block in a group fails, the others will be replaced which is my understanding of what you are trying to do. Note that you will have to set the group number of those blocks (from the "Corrective" tab in the maintenance properties of the block) to a number other than zero as zero represents no group.
Arai

[croseward]

Thank you for your reply Arai.M. If the whole group takes 1 hour to repair/replace, do I put a fixed duration of 1 hour for each item in the group or just a single item? Thanks again....

[Arai.M]

Each item will use the properties set at the block level. This allows you to have maintenances that would take different times/use different resources for different items. You can change the properties of more than one block simultaneously from the Item Properties Table from the Project Menu. If all these items are identical and in a series/paralel/k-out-n configuration, you could also use a multi block so that all properties are identical even though the items are identical but independent.
Arai