Engine Control System - Severity of an engine failure ('dies') in a truck or bus

S

SoftwareEng

#1
"You are doing an FMEA on an engine control system for an on-highway truck/bus. You are considering a failure mode where the engine dies without any warning. What severity do you give this item, and why?"
 

Sidney Vianna

Post Responsibly
Staff member
Admin
#2
How conservative you want to be?

SoftwareEng said:
"You are doing an FMEA on an engine control system for an on-highway truck/bus. You are considering a failure mode where the engine dies without any warning. What severity do you give this item, and why?"
You should provide the severity scale.
I would rate this as very severe. Highways are extremely dangerous. An unannounced engine failure could lead to diminished vehicle control (loss of power steering, power braking, etc....). The situation could lead to a collision ending up in casualties and severe injuries.
 

Craig H.

Quite Involved in Discussions
#3
I would give it a very high rating. Why?

Often when the engine dies, so do control devices, like power steering and brake boosters. There have been fatalities where a truck engine quit, and the driver was not strong enough to turn the truck away from a most unfortunate victim. Pretty serious stuff.
 
#5
The severity (as I was told) depends upon who the next customer is. For my example: I was a Tier 2 supplier (at the time) of airbag filters. The Filter went into the Airbag Module (my Customer's product) that was sold to GM for production vehicles. My Customer told me that the severity rating of my Filter failing was not very high because I was not the Tier 1 supplier. My Customer's FMEA was the final "say" and that FMEA rated it as a very high rating. Like a good little soldier, I did what my Customer told me to do and left that potential failure at a medium failure (Middle of the scale).

Does that sound wrong to anyone? :confused:
 
J

jmp4429

#6
Either way, I would rank it very high for the reasons stated above. Here, we rank engine failure with warning a 9 out of 10 for severity. If the failure could occur without warning, we rank it a 10.
 
#7
jmp4429 said:
Either way, I would rank it very high for the reasons stated above. Here, we rank engine failure with warning a 9 out of 10 for severity. If the failure could occur without warning, we rank it a 10.
Yes - I agree. :agree1: I had originally placed the rating at very high but when I submitted the FMEA, I was told (by my Customer) to change it.
 

Helmut Jilling

Auditor / Consultant
#9
Lee said:
The severity (as I was told) depends upon who the next customer is. For my example: I was a Tier 2 supplier (at the time) of airbag filters. The Filter went into the Airbag Module (my Customer's product) that was sold to GM for production vehicles. My Customer told me that the severity rating of my Filter failing was not very high because I was not the Tier 1 supplier. My Customer's FMEA was the final "say" and that FMEA rated it as a very high rating. Like a good little soldier, I did what my Customer told me to do and left that potential failure at a medium failure (Middle of the scale).

Does that sound wrong to anyone? :confused:

D**n customers. Tell em to read the *%&#%@ FMEA Book. It explains the severity ratings very clearly, and it has NOTHING to do with tier. It has to do with the assembly plant and the end user of the Friggin' Vehicle.
Why do customers make this so complicated? :mad:

If it is likely to kill someone, ummm...let's see, a 2, 4...5? Sheesh...didn't we just have a thread on common sense wasn't very common...?
 
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M

Michael Walmsley

#10
In a case of potential litigation, it will all come back down to you and your customer. You will see your customer bailing ship and pointing the big finger at you. People will ask "Why did'nt you read the manual". Lawyers will ask "Were you trying to save time and money over this potential issue by burying it ".

Do you and your company a big favor.
Implement a corporate policy to make your FMEA's proprietary,thus not allowing the transfer to your customer for potential "doctoring" or distribution on their end. Get your corporate legal behind you.

Next, do what is right and hold to it. Many times a customer will have shared responsibility for the issue and not want to do anything with it. They will apply pressure on you to revise your document. OR They may be graded during their yearly employee review by how risk free their project was and they will apply pressure to you to revise the document so that they can look good.

Two wrongs do not make a right.

Tell them to pound sand. :mad:

Been there,Done that!!!!
 
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