Interrupts: can be lost?

On 30/07/2020 02:53, Rick C wrote:

> 
> You do not understand, which shows in your use of the term
> "desirable".
> 
> This is getting absurd.  You want to make the issue about the whim of
> a manager or myself and you don't understand that redesigning a
> produce at times is literally not an option because of the huge
> expense.  You must not have worked on anything that needed more than
> just testing and it was out the door.
> 
> My current product had to go through various levels of certification
> before it could be used.  A part on the board is getting expensive to
> buy and eventually will be unavailable.  I might be willing to design
> a new board with a different part, but the company who buys them may
> not be willing to pay for the certifications.  At that point the
> product will be dead.

Almost every serious product needs some level of certification.  And for 
almost every serious product, there will be multiple critical parts for 
which there is no drop-in second source with identical characteristics. 
  And even when second sources exist, there will be no more guarantees 
that they will be produced longer than the original part.  And for 
almost every serious product, the engineering costs for re-design and 
re-certification are high if parts do end up needing replaced.

You are not in some special situation here - this is life for 
electronics designers and producers the world over.  There are all sorts 
of ways to limit the risks and limit the resulting costs.  Requiring 
"second source" for one component is one possibility - but it is rarely 
a good idea overall.  It's better to run the risk of having to pay some 
extra costs for a re-certification ten years in the future than to be 
guaranteed to pay extra costs now for trying to design the product with 
a hopelessly outdated device.

But one thing you can be sure of - there are no fixed answers that 
always apply.  You deal with each project in the way that works best for 
that project.

And if you are a good designer and project partner, when a customer 
makes a requirement that you think is likely to be a bad idea, you 
question it.  You challenge it.  You try to find alternative solutions 
that will give a better result overall for the project.  (It's unlikely, 
however, that the best alternative is "fire the manager" !)  The 
customer is /not/ always right - at least not at first.  As an 
electronics designer and consultant, it is part of your job to tell the 
customer if you don't think they are asking for the right thing - if you 
give them what they ask for, not what they want or need, then you are 
doing them a disservice.  Of course this will mean that sometimes a 
customer will move on and find an alternative supplier.  That's part of 
the job too.

> 
> There are apps where the certs are very expensive, like space or
> various safety related uses.  Nuke plants are an example.
> 

Sure - and what percentage of electronics development projects do these 
account for?  Rounded to the nearest percent, nothing.  (And I've worked 
on a few safety-related projects - second source was never an issue.)

> I'm not going to continue to bat this around with you when you
> clearly are not getting the concept.
> 

On Tuesday, August 4, 2020 at 2:40:24 PM UTC-4, David Brown wrote:
> On 30/07/2020 02:53, Rick C wrote:
> 
> > 
> > You do not understand, which shows in your use of the term
> > "desirable".
> > 
> > This is getting absurd.  You want to make the issue about the whim of
> > a manager or myself and you don't understand that redesigning a
> > produce at times is literally not an option because of the huge
> > expense.  You must not have worked on anything that needed more than
> > just testing and it was out the door.
> > 
> > My current product had to go through various levels of certification
> > before it could be used.  A part on the board is getting expensive to
> > buy and eventually will be unavailable.  I might be willing to design
> > a new board with a different part, but the company who buys them may
> > not be willing to pay for the certifications.  At that point the
> > product will be dead.
> 
> Almost every serious product needs some level of certification.  And for 
> almost every serious product, there will be multiple critical parts for 
> which there is no drop-in second source with identical characteristics. 
>   And even when second sources exist, there will be no more guarantees 
> that they will be produced longer than the original part.  And for 
> almost every serious product, the engineering costs for re-design and 
> re-certification are high if parts do end up needing replaced.
> 
> You are not in some special situation here - this is life for 
> electronics designers and producers the world over.  There are all sorts 
> of ways to limit the risks and limit the resulting costs.  Requiring 
> "second source" for one component is one possibility - but it is rarely 
> a good idea overall.  It's better to run the risk of having to pay some 
> extra costs for a re-certification ten years in the future than to be 
> guaranteed to pay extra costs now for trying to design the product with 
> a hopelessly outdated device.
> 
> But one thing you can be sure of - there are no fixed answers that 
> always apply.  You deal with each project in the way that works best for 
> that project.
> 
> And if you are a good designer and project partner, when a customer 
> makes a requirement that you think is likely to be a bad idea, you 
> question it.  You challenge it.  You try to find alternative solutions 
> that will give a better result overall for the project.  (It's unlikely, 
> however, that the best alternative is "fire the manager" !)  The 
> customer is /not/ always right - at least not at first.  As an 
> electronics designer and consultant, it is part of your job to tell the 
> customer if you don't think they are asking for the right thing - if you 
> give them what they ask for, not what they want or need, then you are 
> doing them a disservice.  Of course this will mean that sometimes a 
> customer will move on and find an alternative supplier.  That's part of 
> the job too.
> 
> > 
> > There are apps where the certs are very expensive, like space or
> > various safety related uses.  Nuke plants are an example.
> > 
> 
> Sure - and what percentage of electronics development projects do these 
> account for?  Rounded to the nearest percent, nothing.  (And I've worked 
> on a few safety-related projects - second source was never an issue.)
> 
> > I'm not going to continue to bat this around with you when you
> > clearly are not getting the concept.
> >

Everything you posted is irrelevant, immaterial or tangential to the issue of second sources.  So, nothing to reply to. 

Enjoy. 

-- 

  Rick C.

  -+-- Get 1,000 miles of free Supercharging
  -+-- Tesla referral code - https://ts.la/richard11209

On 8/4/20 2:40 PM, David Brown wrote:
> 
> And if you are a good designer and project partner, when a customer
> makes a requirement that you think is likely to be a bad idea, you
> question it.  You challenge it.  You try to find alternative solutions
> that will give a better result overall for the project.  (It's unlikely,
> however, that the best alternative is "fire the manager" !)  The
> customer is /not/ always right - at least not at first.  As an
> electronics designer and consultant, it is part of your job to tell the
> customer if you don't think they are asking for the right thing - if you
> give them what they ask for, not what they want or need, then you are
> doing them a disservice.  Of course this will mean that sometimes a
> customer will move on and find an alternative supplier.  That's part of
> the job too.
> 

And sometimes the customer is VERY important, spending more than the
next several possible customers for this sort of product combined (and
the power to prevent you from selling to some of them). If you complain
to loudly that they don't really know what they want, they are more than
willing to find other suppliers, and if you make them too upset, they
might black list you, effectively making you change your line of business.

There ARE good reasons to spec parts to have second sources (and note,
second source does NOT mean someone else has made a knock off clone of
the part, for this purpose, second source tends to mean the company has
an official second source agreement with the other firm.

On 05/08/2020 04:32, Richard Damon wrote:
> On 8/4/20 2:40 PM, David Brown wrote:
>>
>> And if you are a good designer and project partner, when a customer
>> makes a requirement that you think is likely to be a bad idea, you
>> question it.  You challenge it.  You try to find alternative solutions
>> that will give a better result overall for the project.  (It's unlikely,
>> however, that the best alternative is "fire the manager" !)  The
>> customer is /not/ always right - at least not at first.  As an
>> electronics designer and consultant, it is part of your job to tell the
>> customer if you don't think they are asking for the right thing - if you
>> give them what they ask for, not what they want or need, then you are
>> doing them a disservice.  Of course this will mean that sometimes a
>> customer will move on and find an alternative supplier.  That's part of
>> the job too.
>>
> 
> And sometimes the customer is VERY important, spending more than the
> next several possible customers for this sort of product combined (and
> the power to prevent you from selling to some of them). If you complain
> to loudly that they don't really know what they want, they are more than
> willing to find other suppliers, and if you make them too upset, they
> might black list you, effectively making you change your line of business.

Of course - as I said, there is no single right answer.  Occasionally it 
even makes sense to spend time, effort on money working on something 
that you know is fruitless, because it is important for keeping the 
customer.  And obviously you are more diplomatic in how you put things 
to the customer than one might be in a newsgroup!

We have had cases of a customer come to us with concrete requirements, 
have us tell them that the requirements are not realistic but we can 
help them with alternative ideas and solutions, and they have chosen to 
go away and find another development company.  Then after having wasted 
significant time and money with another company that tried and failed to 
fulfil the original requirements, they came back to us to find out how 
to get what they actually need, not what they asked for.

> 
> There ARE good reasons to spec parts to have second sources (and note,
> second source does NOT mean someone else has made a knock off clone of
> the part, for this purpose, second source tends to mean the company has
> an official second source agreement with the other firm.
> 

Oh, sure.  And occasionally those reasons might be good enough to make 
it worth doing.  But usually it's just wishful thinking on the part of 
the customer.  After all, from the customer's viewpoint, they have good 
reason for requiring the device to be small, cheap, long-lasting, 
suitable for production anywhere, and so on - that doesn't mean the 
requirements are realistic or the best choice for the project as a 
whole.  Helping the customer get the requirements right is part of the job.