Nursing side - The problem with linking productivity with staffing ratios is that there is often an inverse relationship (i.e., the more patients, the less productive a nurse actually is). Part of the issue is the way that productivity is being defined, which often differs from hospital to hospital and is usually done by someone who doesn't know a blood pressure cuff from a scalpel. In the land of NICU, most nurses I know would be inclined to define productivity based on the depth of quality care they can provide for their patients, something that suffers tremendously when we are forced/pushed into assignments that have us running around like blue chickens with our heads cut off.
Business side - The staffing ratios are designed to be a guide only, they can (and should be modified) as the patient care warrants, but as prmenrs said correctly, you have to be able to back it up. AWHONN has recommended guidelines for staffing and so does NANN, but they differ in that NANN doesn't generally allow 4 babies to 1 nurse as it only really considers Level III NICU and not Level II special patients. If the unit outcomes are good and the patients are receiving care at an appropriate level as defined by unit standards, why would you need more nurses? Are the tasks that you need assistance with something that an assistant could do for a third of the cost? Productivity is likely based on hours per patient day which IMHO...sucks and is relatively useless in actually determining how much time is spent with a patient. Since we are paid based on case-mix indices, in order to provide that 1:1 care for a sick infant, other people might have to be 1:3 or 1:4 as their acuity doesn't justify an extra staff member at this time.
A major, major issue is that often both sides don't have a clue what the other is doing/dealing with. I can't stress enough that more education in nursing programs
needs to be on the financial aspect of healthcare and that orientation to administrative and financial positions in hospitals should include time spent on a nursing unit with the staff. You can say that "they don't get it" because they don't and chances are neither do you (I'm not referencing any poster, just ranting in general). If we really want to provide the best care for our patients in the most efficient, economical way, we have to understand the totality of hospital operations, not just our own specialty whether it be NICU or grilling the worse Grade-E hamburgers a hospital cafeteria can purchase.
TL;DR: Nurses, if you need better staffing, document why. Managers - We only have so much money to go around and what we are getting paid for this acuity doesn't cover more nurses. All of us, let's work together to fix this junk.