I have an IDIQ, FFP production contract. My customer wants to slow down the contractor's production line by half(because funding is less, need is less and usage rate going down). I have a current Delivery Order on contract for 100k units over a period of about a year. My main question is can i mod the delivery order to cut the quantity per month? Which means the period of performance would be longer. I assume i can as long as the contractor agrees to it(bi lateral mod)?