Bolts And Brainstorming

  • Thread starter Andreii
  • Start date
  • #1
53
0

Main Question or Discussion Point

Hi everyone
I am starting on my thesis for university and I would like to please for suggestions.
I have topic that belongs to quality assurance and it is FMEA Analysis In The Manufactory Of Bolts. I have done some research on google, picked up some worldwide companies where are producing bolts. I messaged them and wanted to ask if is possible to get from them some examples how can be FMEA (with its subanalysis process fmea, product fmea,...) used on exactly definited environment - bolts in all four processes;

- cold heading
- rolling
- milling
- thermal treatment

I skipped surface treatment because I won't include it in my thesis, the reason for this is we don't have this section in ''our'' manufactory of bolts where I work(ed).

So I wanted to please for some examples, of course I mentoined that I am very aware of copyrights and also mentoined for what purposes do I need this.
And? Not a single e-mail reply from anyone.

So I kept studying FMEA Analysis and of course, since I haven't even begun on thesis but only prepearing it, I still study FMEA. In the steps of this processes says that I need to brainstorm 3 different lists:

- what kinds of failures (or defects on bolts in product FMEA) could occur in the manufactory of bolts. So a list of thousands (or as much as possible) of possibilities whatever could go wrong.

- list of possible consequences (= effect modes) to each failure or occured defect. Of course every failure / defect could have more than one consequences.

- list of possible solutions how could I fix the failure / defect or decrease the consequence

In the basic steps of FMEA Analysis aren't included causes of failures / defects. Why is beyond me but this (causes) is almost offtopic of this message now.

I have to do all by myself because its my thesis and noone in manufactory can help me in any way. So if I try to break some rules about Brainstorming - how could it be done (by more than one people) and if I try to do it alone, I get lack of ideas. Tried to think a lot but no success.

I could gather some books relevant to ''bolts'' topic (which doesn't neccessary mean relevant to FMEA analysis) and try to negative almost every sentence. This way I could get a very huge list of whatever could go wrong but I cannot get, at least this way not, second and third list (consequences and solutions).

In reality something like this probably doesn't exsist, I guess (its true I might be wrong also) no manufactory on the world has anything like that. So I would have to create those three lists somehow because I want to have them. Thesis is a huge project that consist of many pages. At the end only quality is important and not amount of those pages but I still have to fill the pages somehow and prepare subjects for FMEA analysis.

My question:

Does anyone know any good books that I should use? Through reading them I would be filling the entries in all three lists. Also where I should look for ideas about bolts? Does anyone have any contact with manufactories of bolts?

Any comment from users with experiences or knowledge about bolts is more than welcome and very appreciated as well.
 

Answers and Replies

  • #2
brewnog
Science Advisor
Gold Member
2,711
7
The FMEA for a bolt shouldn't run to more than a couple of pages, so if you think it will you obviously haven't understood the premise of an FMEA.

Do not compound effects; that is "the bolt fails, causing the steering wheel to fall off, causing the bus to career off the road, causing a family of small badgers to be squashed".

For your bolt, depending on the application (in this case a shelf bracket bolt), you should end up with something like this for a system FMEA:

- Start with the function. ("Fastens shelf to wall"). If you haven't got some good verbs in here ('fasten', 'contain', 'transport', 'carry', 'conduct' etc) you've done something wrong.
- List the anti-functions. ("Shelf is not fastened to wall"). These are your failure modes. For multiple functions you should have multiple anti-functions.
- List the immediate causes of the failure happening. ("Books fall down"). As before, there should be no "books crush baby hedgehog on floor" secondary causes.
- Now, here's the key bit. List the potential causes of the failure mode; not of the effect. "bracket bends", "bolt breaks" etc.

Score your FMEAs using severity for the effect, and occurance for the cause (not the failure mode).

Now, you should have an idea where to focus further studies. For instance, your 'occurance' for 'bolt fails' may be high, so your component FMEA may run as follows:

Function: Clamps shelf bracket to wall
Failure mode: Clamping between bracket and wall lost
Effects: Bracket wobbles, bracket comes off wall.
Causes: Insufficient thread engagement, inadequate torque, excessive torque, poor head formation etc.

For your design FMEA, assume everything is made correctly as you're trying to expose weaknesses in your design. For your process FMEA, assume it's designed correctly.

There are hundreds of books on this by the way.
 
  • #3
53
0
Brewnog thank you for your reply. I will quote your part of text to say my understanding / comments of what I have learned only and not having anything against your statements. With quotes is easier to find out to which part of text do I comment.

The FMEA for a bolt shouldn't run to more than a couple of pages
Thesis should be on around 80 pages (around 50 for practice - using FMEA in exact environment - bolts) but amount of pages doesn't really matter, what is on pages is the subject which counts. Writting a feedback is not something what steps of accurately done FMEA analysis require. In neither of steps (source: book ''The Basics Of FMEA'') says that I need to write down any feedback. If I do this anyway, it won't hurt. Its just a benefit.
So I would have to do the several different analysis then.


Do not compound effects; that is "the bolt fails, causing the steering wheel to fall off, causing the bus to career off the road, causing a family of small badgers to be squashed".
effect = consequence. This ''equation'' should be correct.

you should end up with something like this for a system FMEA
I would use process FMEA or product FMEA. I don't know yet for what and specially when is used system and design FMEA but example, which your wrote, sounds to me more like process FMEA.

- Start with the function. ("Fastens shelf to wall"). If you haven't got some good verbs in here ('fasten', 'contain', 'transport', 'carry', 'conduct' etc) you've done something wrong.
- List the anti-functions. ("Shelf is not fastened to wall"). These are your failure modes. For multiple functions you should have multiple anti-functions.
- List the immediate causes of the failure happening. ("Books fall down"). As before, there should be no "books crush baby hedgehog on floor" secondary causes.
- Now, here's the key bit. List the potential causes of the failure mode; not of the effect. "bracket bends", "bolt breaks" etc.
As I have seen in the book ''The Basics Of FMEA'', specially at the steps how this analysis must be done, it has nothing to do with any functions or causes. When it comes to brainstorming, its all about naming the failures, consequences and solutions.

Score your FMEAs using severity for the effect, and occurance for the cause (not the failure mode).
Again, this is completely against what I have been reading. Occurance should be for the failure? Score of detection should be included too and it is for the effect (severity) and for cause by your opinion or for failure by my opinion and according to what the book says. I definitely must understand this, if I don't I cannot do anything. And now I am forced to include this book, from where I was studying fmea on the following downloading link:

http://www.sendspace.com/file/inisai

I tried to put it into attachment but the pdf file is for 39 kb too big, also ziping it doesn't help. Attention should be to page number 34 / 104 of pdf file (= page number 23 of page IDs).
I got it from department of quality in our country and did NOT download it online.

There are hundreds of books on this by the way.
You probably understood me that I am trying to collect list of posible failures, effects and solutions - this is what I am asking yes. I would still like to please you if we can further discuss why the causes (and function, by the way, what is this exactly? I cannot determinate what is it and for what purposes could be useful) should be included? I do fully believe you but I still wonder which source says this. I don't see in neither causes or ''function'' whichever relevance to FMEA analysis.

I have found only books on FMEA Analysis. Unfortunately for me, I can probably forget for books that cover FMEA AND bolts at the same time - so FMEA used on bolts. I have been searching this but couldn't find. With saying ''hundreds of books'' you probably meant the books that cover topics of bolts and from this books I could collect those houndreds or thousands of entries in three (four? if causes included) different lists. Which book(s) did you mean? Just typing ''bolts'' on amazon.com is probably not the best idea.
 
  • #4
5,439
7
An area of engineering where such considerations has seen development, both theoretical and practical, is the use of holding down bolts for railings and the failure modes of the whole assembly.

Much work on this has been done at the former UK Road Research Laboratory for designing bridge parapets and motorway 'crash barriers'.

I do believe that the Institute of Naval Architects did similar work years back for marine railings.

Indeed any manufacturer of components/installations that have to fail/hold firm at certain prescribed loads and when they do fail, fail in a certain prescribed manner / location /section, will have considered such matters.
 
  • #5
AlephZero
Science Advisor
Homework Helper
6,994
291
Im feeling confused by this thread. In the OP you said "FMEA Analysis In The MANUFACTORY Of Bolts". So far, everybody has talked about "FEMA Analysis In the USE Of Bolts". That is a rather different topic.

FEMA for bolt manufacture is about failing to make a bolt that meets its specifications (geometry, material properties, etc), not about shelves or motorway crash barriers falling apart.

I suppose that so far as a bolt manufacturer is concerned, the consequences of failure to meet the specification are things like

Product is not marketable (i.e. scrap)
Product can only be marketed as a lower quality / wider tolerance item than it was intended to be (i.e. reduced profit margin)
More rigorous quality control inspection required (i.e. increased manufacturing cost).
etc.
 
  • #6
brewnog
Science Advisor
Gold Member
2,711
7
Thesis should be on around 80 pages (around 50 for practice - using FMEA in exact environment - bolts) but amount of pages doesn't really matter, what is on pages is the subject which counts. Writting a feedback is not something what steps of accurately done FMEA analysis require. In neither of steps (source: book ''The Basics Of FMEA'') says that I need to write down any feedback. If I do this anyway, it won't hurt. Its just a benefit.
So I would have to do the several different analysis then.
Surely your thesis isn't just some FMEAs; but a discussion thereof? I was telling you what a typical FMEA looks like, not what your thesis should look like.

effect = consequence. This ''equation'' should be correct.
It's what happens as a direct result of the failure mode occuring. See my earlier posts on compounding effects ('consequences'). There's a subtle difference, perhaps the language barrier doesn't help.

As I have seen in the book ''The Basics Of FMEA'', specially at the steps how this analysis must be done, it has nothing to do with any functions or causes. When it comes to brainstorming, its all about naming the failures, consequences and solutions.
Your book talks bollocks; solutions should only be saught when you have got a good analysis of which causes of failure modes need priority. An FMEA book which doesn't consider causes isn't worth reading, because only by understanding the cause of each failure mode can you design them out.

Again, this is completely against what I have been reading. Occurance should be for the failure?
No. Occurance is about the probability of the CAUSE happening.

Score of detection should be included too and it is for the effect (severity) and for cause by your opinion or for failure by my opinion and according to what the book says.
I didn't mention detection so I don't know how you can assume my opinion on that...

You probably understood me that I am trying to collect list of posible failures, effects and solutions - this is what I am asking yes.
The whole point of an FMEA is to have a team of people with some subject knowledge to assess and mitigate risks in context. If you're looking for pre-written lists which you expect to be able to apply to your example then you've entirely missed the point. It's not about filling in a form, it's about getting together and putting some proper thought into your problem.

I would still like to please you if we can further discuss why the causes (and function, by the way, what is this exactly?
I don't understand this.

I cannot determinate what is it and for what purposes could be useful) should be included? I do fully believe you but I still wonder which source says this. I don't see in neither causes or ''function'' whichever relevance to FMEA analysis.

I have found only books on FMEA Analysis. Unfortunately for me, I can probably forget for books that cover FMEA AND bolts at the same time - so FMEA used on bolts. I have been searching this but couldn't find. With saying ''hundreds of books'' you probably meant the books that cover topics of bolts and from this books I could collect those houndreds or thousands of entries in three (four? if causes included) different lists. Which book(s) did you mean? Just typing ''bolts'' on amazon.com is probably not the best idea.
I meant one of the 2,343 hits that Amazon returns when you search for "FMEA". Hell, I'm not going to do your shopping for you, but you've got some grave misconceptions about what you're supposed to be doing, I tried to point these out to you but you obviously require something more than an engineer with 6 years experience of running FMEAs (who, incidentally, sat a 4 day FMEA workshop taught by the guy who implemented the process at Ford Motor Company) to convince you. Read the reviews, but you won't find a book on "how to do my thesis".
 
  • #7
brewnog
Science Advisor
Gold Member
2,711
7
Im feeling confused by this thread. In the OP you said "FMEA Analysis In The MANUFACTORY Of Bolts". So far, everybody has talked about "FEMA Analysis In the USE Of Bolts". That is a rather different topic.

FEMA for bolt manufacture is about failing to make a bolt that meets its specifications (geometry, material properties, etc), not about shelves or motorway crash barriers falling apart.
Yeah, I wasn't sure that even the OP knew he was talking about the manufacturing process, but you're right. I find design FMEAs much easier to use as examples though.
 
  • #8
53
0
Indeed any manufacturer of components/installations that have to fail/hold firm at certain prescribed loads and when they do fail, fail in a certain prescribed manner / location /section, will have considered such matters.
I asked manufacturers/companies for examples of FMEA analysis. Those message often comes to management deparment so at the beginning of the message, I told them to forward it to the person reponsible for Quality Assurance. Noone replied. Perhaps I should ask for the lists of failures, consequences and solutions instead of examples for FMEA.

Surely your thesis isn't just some FMEAs; but a discussion thereof? I was telling you what a typical FMEA looks like, not what your thesis should look like.
My thesis isn't just about FMEA but using FMEA in exactly definited environment - bolts (with and without screws but this already depends on customer's wishes) and nothing else. Sure there must be some introduction made with ''Theory Of FMEA'' before I move to practice and use it on bolts. But even in theory, I still wonder and don't understand why, when and for what should I use causes and functions. This doesn't say in any FMEA books / tutorials. At least not what I have found.

It's what happens as a direct result of the failure mode occuring.
Yes this is what I call ''consequence'' according to my dictionary. In the book is this expressed as ''effect mode''.

Solutions should only be saught when you have got a good analysis of which causes of failure modes need priority. An FMEA book which doesn't consider causes isn't worth reading, because only by understanding the cause of each failure mode can you design them out.
I still don't understand what you mean here. The steps of process ''How To Do FMEA'' or how to go through it, require failure names (so what could occur but noone wants it to happen), direct result of failure and solution so failure won't appear again OR direct result of failure will decrease.
Cause is expressed as the reason WHY failure occured

Occurance is about the probability of the CAUSE happening.
Ok I understand this. It is one explanation of Occurance mark. Second explanation is: In which frequency (time interval) would failure occur. You explained the meaning of ''occurance'' that involves cause but this doesn't neccessary mean that this mark is scored for cause. Right? So what do we score ( ! ) is, according to the book, the failure.

I meant one of the 2,343 hits that Amazon returns when you search for "FMEA".
Oh ok, I thought you meant the books on topic Bolts and their ''behaviour'' in the manufactories. This is what I was searching so I can construct the lists.

I tried to point these out to you but you obviously require something more than an engineer with 6 years experience of running FMEAs (who, incidentally, sat a 4 day FMEA workshop taught by the guy who implemented the process at Ford Motor Company) to convince you.
Its not about convincing me. I fully believe you but there is a difference between believing and not understanding or being confused by the offical book. So thats why I was/am wondering about causes and ''functions''.
 
  • #9
53
0
Is anyone willing to suggest where should I look or which company (worldwire) should I ask for those lists? Thank you.
 
  • #10
53
0
anyone?
 
  • #11
586
2
I asked manufacturers/companies for examples of FMEA analysis. Those message often comes to management deparment so at the beginning of the message, I told them to forward it to the person reponsible for Quality Assurance. Noone replied. Perhaps I should ask for the lists of failures, consequences and solutions instead of examples for FMEA.
The problem you're experiencing (no response from the companies) is likely due to a couple of basic reasons: [1] Proprietary data is seldom provided to anyone outside of the company. When it is, it typically requires lawyers and Non-Disclosure Agreements. [2] Product liability.

As for books on the subject, searching https://www.amazon.com/s/ref=nb_sb_...s&field-keywords=fasteners&sprefix=fasteners" returns several good possibilities, such as
"https://www.amazon.com/dp/0824775546/?tag=pfamazon01-20"
"https://www.amazon.com/dp/1410224910/?tag=pfamazon01-20"
"https://www.amazon.com/dp/0920855067/?tag=pfamazon01-20"
 
Last edited by a moderator:
  • #12
53
0
anyone?
 

Related Threads on Bolts And Brainstorming

  • Last Post
Replies
16
Views
5K
  • Last Post
Replies
12
Views
4K
  • Last Post
Replies
10
Views
499
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
5
Views
17K
  • Last Post
Replies
6
Views
3K
Replies
3
Views
591
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
4
Views
3K
  • Last Post
Replies
4
Views
14K
Top