1. What is the process of increasing quantities on a requirement type contract that was competitive? Can you just increase quantities via a modification with no additional documentation or is additional documentation needed (i.e. J&A) to do so?
2. What is the process of increasing quantities on a single award IDIQ contract that was competitive? Can you just increase quantities via a modification with no additional documentation or is additional documentation needed (i.e. J&A) to do so?
Applicable guidance to your question can be found in FAR 17.204, 10 USC 2304, FAR 13.501, and FAR 13.106-1. According to FAR 17.204, delivery orders placed must be within the ordering limits for additional supplies and services specified in the indefinite-delivery contract According to 10 USC 2304, a delivery order may not increase the scope, period or maximum value of the basic contract under which the order was issued. The new order would be invalid if it increased the scope, period or maximum value of the contract. The scope, period or maximum value of the contract can only be increased by a modification to the contract. In the AAP background information, you said that the indefinite-delivery contracts were competitively awarded. Therefore, you'll need to accomplish a Justification and Approval in accordance with FAR 6.303 prior to negotiating a modification to increase the order quantity for the basic contracts.
You also said that some of the Requirements contracts were under the SAT. If that's the case, then FAR Part 6 is not applicable to those contracts (but see FAR 13.501 for requirements pertaining to sole source acquisitions of commercial items under subpart 13.5). For contracts under the SAT, you'll also want to take a look at the guidance in FAR 13.106-1 Soliciting competition. Before proceeding any further, I highly recommend discussing the modifications with your Contracting Officer, Competition Advocate and legal advisor to ensure they comply with the limits in the existing contracts as well as any applicable laws and regulations.
See: FAR 17.204 Contracts. — (a) The contract shall specify limits on the purchase of additional supplies or services, or the overall duration of the term of the contract, including any extension.
10 USC 2304(e)Contract Modifications.— The scope, period, or maximum value of the contract may be increased only by modification of the contract.