It is hard to provide more specific guidance as "ARP" is used often in military and commercial Lexicon.  If your procurement is weapon system related; see

DFARS 207.106(b)(S-73) for guidance on who is authorized to waive the AP. 

If not, go to the DAU Adaptive Acquisition Framework page; if your acquisition is related to one of the Pathways; click on it and see if there is guidance (exception or wiaver) there.  There are examples of waiver authorities for streamlining.

If none of those apply, you seek out a one-time deviation in accordance with the DFARS and your Agency Supplement (see DFARS subpart 201.4).