FAI should be on the first series devices, not prototypes. If the regulatory timeline is constrained you may decide to use digital manufacturing for the first series and switch to other processes (eg injection mouldings) later with the associated change management, testing, etc.

Caitlin Morse, PMP In working with a variety of clients, "prototyping" has different meanings to different people. In the context of this question, what comes next? Do you have additional engineering builds after the prototyping phase?
I would recommend at least one round of FAI before freezing your design for DV procurement, build and test. You want to know you are evaluating and addressing true design issues, not just your supplier's failure to meet the design. By the same token, if your engineers are designing without standard supplier tolerances by commodity taken into consideration, you want to know about those issues early enough to make appropriate changes.
Assuming there will be additional evaluation after prototyping on units built using more production equivalent processes, let the engineers prototype what they need to without slowing them down with premature FAI.

Caitlin Morse, PMP Mohamed Zitouni,
My first response would be to say the same thing Derek did, that prototyping is often going to use quick turn manufacturing processes, etc that are not going to be used moving forward, so FAI would be overly burdensome at this stage.

However, towards the end of your statement you talk about the device complying with requirements/regulations. In my experience, if you are evaluating a design against requirements by doing structured, documented testing, you should be doing FAI on critical dimensions as defined by your tolerance stack and risk analysis. How can you evaluate if the design meets the requirements if you don't know if the product in your hands meets the design.

Let engineers do the prototyping they need to in order to figure out their design concepts with minimal interference. Once they think they have a working design worth evaluating, it's time to make sure you have the proper supply chain controls in place (controlled/released drawings, reasonable tolerances, FAI, appropriate sampling plan, documented test methods and protocols, etc) to ensure that any "design" issues that arise are truly with the design and not with the supplier failure to meet the print.

Matthew Romey I agree with Caitlin, it depends on the nature of your prototype. If the manufacturing process for the part(s) in question will not change, then you might be saving time by doing the FAI now. The sooner you discover issues with the supplier the less risk you will present to the project schedule. Of course, if the supplier's process will change from prototype to released part, then sure, a FAI is probably a waste of time.

Cornelio Florian It appears you are in the early stages of product development..It would be important to follow some standard like APQP. this should guide you to the phases where it is appropriate to perform FAI. (Take into account applicable regulations)

I would take it further in development myself until you have elaborated many aspects to best function and then take it to other experts for evaluation and improvements if any. Depends on your product development expertise how far you can take it and Funds available to engage SMO/ Jukka

You don' have to call for FAI at its full shape but building prototype being blind is risky. Discuss APQP phases with your supplier and define what is required to be provided each step... from simple dimensions up to ppk on the next stages having FAI from Pilot run finaly. Best!

Some machine shops produce FAI’s at no charge - I work with one. Let me know if you need any milling or turning work.
Best, Shawn

Mark Proulx, CQA, cSSBB Mohammed Zitouni I think Adam Binias is a little closer to the answer you're looking for. As a former R&D Engineer, my supplier-related questions only came after generating a dFMEA and running my process efficiencies (Cp, Cpk, Pp, Ppk). First articles are only valuable after you have assigned criticality to your parts and you can lock in your design tolerances.

On another note, FAI may not be enough to ensure quality if you have not properly assessed your suppliers in the first place and are confident they can deliver what you've ordered. There may need to be an ongoing program of heightened inspections if the criticality or risk is high enough. There is a reason for using FAI and not some other form of control.

Hi, just follow design control, you have prototypes accepted criteria,then go to next stage following ECN control