FAI (First Article Inspection) during Assembly of Sub-Assemblies Only

[Sohail]

1. A firm's division assembles the manufactured parts. All individual parts do go thru FAI in the first production run. But when all parts are assembled together into a single product, no FAI is done on first assembled product. Is it ok? Does "first production run" also includes "the first assembled product"?

2. A firm says, all of its product dimensions in all drawings are key characteristics and are monitored during QC. So we dont need to identify the key characteristics. Is it ok?

 

[ScottK]

Re: FAI in assembly

1. A firm's division assembles the manufactured parts. All individual parts do go thru FAI in the first production run. But when all parts are assembled together into a single product, no FAI is done on first assembled product. Is it ok? Does "first production run" also includes "the first assembled product"?

2. A firm says, all of its product dimensions in all drawings are key characteristics and are monitored during QC. So we dont need to identify the key characteristics. Is it ok?

I can speak to 1 from a medical device perspective: In every situation I've worked in there is both component and final assembly inspection. Good components does not guarantee that they are assembled properly. I suppose it's possible, but you're need to validate the assembly process and demonstrate a very low error rate.

2. Many places I've worked have have fully dimensioned drawings and inspection drawings. On the inspection drawings all dimensions are CTQ and must be measured. This is called out in the design and development procedures.

 

[Joelbear5]

1. A firm's division assembles the manufactured parts. All individual parts do go thru FAI in the first production run. But when all parts are assembled together into a single product, no FAI is done on first assembled product. Is it ok? Does "first production run" also includes "the first assembled product"?

2. A firm says, all of its product dimensions in all drawings are key characteristics and are monitored during QC. So we dont need to identify the key characteristics. Is it ok?

In aerospace, when following AS9102 First Article Inspection, all detail parts (components) are inspected, and the assemblies are also inspected. The form has a place to record all first article inspection numbers of its detail parts. I would assume this requirement would be placed in the Purchase Order somewhere to even do a first article inspection.

 

[Mikishots]

1. A firm's division assembles the manufactured parts. All individual parts do go thru FAI in the first production run. But when all parts are assembled together into a single product, no FAI is done on first assembled product. Is it ok? Does "first production run" also includes "the first assembled product"?

2. A firm says, all of its product dimensions in all drawings are key characteristics and are monitored during QC. So we dont need to identify the key characteristics. Is it ok?

AS9102 states "This Aerospace Standard applies to assemblies sub-assemblies, and detail parts including castings and forgings."

A key characteristic can also be performance, service life and producibility - I don't see how one can be dimensioning those.

Some critical items can also be defined as key characteristics because of the need for control of variation.

 

[dsanabria]

1. A firm's division assembles the manufactured parts. All individual parts do go thru FAI in the first production run. But when all parts are assembled together into a single product, no FAI is done on first assembled product. Is it ok? Does "first production run" also includes "the first assembled product"?

It is not OK - A complete FAIR must be done of individual parts and assembly

2. A firm says, all of its product dimensions in all drawings are key characteristics and are monitored during QC. So we dont need to identify the key characteristics. Is it ok?

If the firm is making that statement - then you need to comply and identify the key characteristics. (NOTE: This could qualify - not knowing the product - as an examples of lazy design and development, in which every item would go to default and everything would be a "key characteristic")