Hi Naveen,
When ever delta fails, first analyze the error and solve it.
Later you can try to trigger repeat delta By making technical status to red and trgger delta info pack.
it may asks for repeat delta and continue it.
if your delta failed two times continuoisly then you may lost delta data.
Need to load such missed records thru repat full request with proper selections.
Repeat delta need to run by manual not thru process chain.
at process chain there is no option to run repeat delta.
But you may have repeat option but not repeat delta.
Thanks