Task: Text to Code
Input (English): Step 1: For each row in Parts table, find the corresponding rows in Part_Faults table.
Step 2: find the summation of chargeable_amount of each value of Parts's part_id in the results of step 1.
Step 3: find Parts's part_id, part_fault_id of step 1 results with smallest value in the results of step 2
Output (English): SELECT T1.part_id , T2.part_fault_id FROM Parts AS T1 JOIN Part_Faults AS T2 ON T1.part_id = T2.part_id GROUP BY T1.part_id ORDER BY Sum ( T1.chargeable_amount ) Asc LIMIT 1