PSP Encumbrance Liquidation Exception

select 	papf.full_name,
	paf.assignment_number,
	ppf.payroll_name,
	decode(pepa.assignment_status,'P','Z',pepa.assignment_status) assignment_status
FROM	psp_enc_process_assignments pepa,
	per_all_assignments_f paf,
	pay_all_payrolls_f ppf,
	per_all_people_f papf
WHERE	paf.assignment_id = pepa.assignment_id
AND	ppf.payroll_id = pepa.payroll_id
AND	papf.person_id = paf.person_id
AND	pepa.payroll_action_id = :p_payroll_action_id 
AND	paf.effective_start_date = (SELECT	MAX(paf2.effective_start_date)
	    		         FROM	per_all_assignments_f paf2
			       WHERE	paf2.assignment_id = pepa.assignment_id)
AND	ppf.effective_start_date = (SELECT	MAX(ppf2.effective_start_date)
	    		          From              pay_all_payrolls_f ppf2
                    		WHERE	ppf2.payroll_id = pepa.payroll_id)
AND	papf.effective_start_date = (SELECT	MAX(papf2.effective_start_date)
	 		          FROM	per_all_people_f papf2
			          WHERE	papf2.person_id = paf.person_id)
order by  4,3,1,2