Ballpoint Pen DFMEA (Design FMEA)

gRrrrrr. One of my assignments in my new job is to create a good DFMEA for a typical ball point pen... the thought being that it will be a good mental exercise so that as I get future applications, I have exercized my mind, and can use the same thought processes to create future DFMEA's.

Grrrr.. I have a headache. do any of you have a good ballpoint pen DFMEA I can study as an example to help me get all this straight in my mind?

(I've discovered I'm really good at PFMEAs.. and having a hard time transferring all that knowledge to DFMEAs.. )

Thanks in advance. The cove is the BEST of the best.

I looked over what you posted and it looks OK to me - It addresses design issues as it should. Sorry I don't have an existing pen design FMEA, but I will say this is interesting.

Revised version..

I've made several revisions.. hopefully even improvements..

TownDawg said:

I've made several revisions.. hopefully even improvements..

Click to expand...

I think what you've got is OK, but I'm not sure about your approach (using an existing design). The other thing I noticed is that there's no consideration given to appearance. A lot of pens are sold based on cosmetics alone, so you would have to make sure that cosmetic concerns are in concert with mechanical considerations.

Unless I am not getting the whole xls in the download or I am misreading what has been done, I do not think you have considered some key aspects of the design. The ball and its function and characteristics including its hardness, smoothness, material properties (compatibility with the ink), dimensional requirements and interface with its housing; the fit of the ball into its housing when it is not in use and when it is in use; the "spring" and its load/compression characteristics, its material and compatibility with the ink; the fit of the ball housing into the sleeve.

Since it is a ball point pen, I did try to search the download I got for details about the ball but did not seem to find any.

Supplemental note: Subsequently downloaded later edited xls which does address some of my points. Except, I am not sure whether the pen would use a stylus or a ball. I do not profess to be intimately familiar with modern ball point design but hope all this is of some help.

Thanks for all your comments. Good information! As for stylus versus ball.. you are right -- even ballpoint have differences, and even though my original DFMEA was trying to address a "ballpoint" my revised version was actually one of those new designs.

Have to run. Work calls. Thanks again!

why don't just use the boundary diagram to 'look' at the component of your pen..

TownDawg said:

gRrrrrr. One of my assignments in my new job is to create a good DFMEA for a typical ball point pen... the thought being that it will be a good mental exercise so that as I get future applications, I have exercized my mind, and can use the same thought processes to create future DFMEA's.

Grrrr.. I have a headache. do any of you have a good ballpoint pen DFMEA I can study as an example to help me get all this straight in my mind?

(I've discovered I'm really good at PFMEAs.. and having a hard time transferring all that knowledge to DFMEAs.. )

Thanks in advance. The cove is the BEST of the best.

Click to expand...

It is good attempt. Consider the following points:

In the DFMEA, you need to assume that a customer is actualy using this product what can go wrong. Even missuse of the product is also can be considered as a failure. Some one puts pen in mouth (the plastic may be toxic material).
In your case, you are coming from functions, which is very good. You can also consider some un-intended functions (ink leak is one example of un-intended function).

Hi, I am new over here. I am trying to prepare a DFMEA report for a sheet metal container. Thanks, your report on a ballpoint pen has helped me lot in understanding DFMEA. Please help me if any one has similar reports so I can use it as reference.

Make sure that the Potential Failure Mode is the opposite of your function.
Split the Current Design Controls in 2 Columns. One for Prevention & the other for Detection.

Recommend to add Functional Block Diagram before DFMEA.
Make sure that you carry the exam example to the end.