I am trying to locate a spare 6ES7315-6FF04-0AB0 CPU fail safe module, latest lead time is 72 weeks

I have been offered 6ES7315-2FJ14-0AB0 module, this is not fail safe. 

Is it suitable to use as a replacement ? 

6ES7315-2FJ14-0AB0 is also a fail safe plc, so it should be possible to use it for replacement.

but you must change something in the project and recompile the Fail Safe Config für the new PLC, only plug an replace is not possible.

Thank you for the information. 

Which part of the PLC is fail safe, unsure of what parts of the CPU it is referring to and how the connected I/O would react 

CJ1976@a

Thank you for the information. 

Which part of the PLC is fail safe, unsure of what parts of the CPU it is referring to and how the connected I/O would react 

 sorry , what you mean with this question?
the PLC is fail safe, this mean you can programming and execute fail safe programms and configuration on the this PLC.

the old PLC is only a DP, if they use FailSafe I/O then is connected with PROFIBUS.

The new offered PLC have als a DP Interface which can be used and additional an PROFINET Interface for connecting decentral i/O.

We don't know the original progem/project, so here can not really say more.

but if you change a filesafe PLC with another type of Fail Safe PLC you must rework the HWConfig (change to new PLC) then compile the complete PLC including the Failsafe and download it to new PLC.

Ok so it is able to be used to program fail safe I/O for guarding and emergency stop circuits. 

Thank you for your answers and time