I've seen this discussed here and there over the years but never seem to see a clear answer. I'll use a laboratory testing requirement for an example...
What contract type would you use for conducting a variety of lab tests (e.g. drug screening, Covid testing, other blood tests, etc.) with fixed unit pricing? This is a relatively simple commercial contract.
1. There about 10 different tests that may be ordered. An estimated number can be specified of each. They will occur far too frequently for individual orders to be placed (e.g., IDIQ). Ex:
Test 1 Est Qty: 50,000 Unit Price: $10.00
Test 2 Est Qty: 25,000 Unit Price: $75.00
Test 3 Est Qty: 30,000 Unit Price: $15.00
Test 4.....
2. A firm-fixed price contract doesn't seem applicable because the range of possible tests needed is very broad.
3. A T&M contract doesn't seem appropriate because there are no labor hours applicable.
4. This has been done as a "fixed price" contract in the past, however that doesn't seem to fit into the umbrella of fixed price contracts at FAR 16.2.