737 Replacement

In article ,
says...




Hardware testing is much more straightforward, because it is much more
difficult to design and build complex hardware, and because hardware
does not have many catastrophic failure modes. Additionally, hardware
is expensive and cannot easily be modified, so there is a much greater
incentive to get it right.



The human brain has many known shortcomings.
Above, for example, is an illustration of one in complete failure mode.

GF

In article ,
says...


A Guy Called Tyketto writes:

Safety can not be weighed against fuel economy.

They can be assigned priorities. I assign a higher priority to
safety, and I'm not alone.


No, they do not, as Airbus has regularly illustrated, beginning way
back in Habsheim. Airbus cares more about fancy press than safety.
They care more about glitter than substance.




All of this moronic blather is unworthy of response, not to mention
disrespectful of everything truthful and of anyone who knows anything about
airplanes.

wrote:
Hardware testing is much more straightforward, because it is much more
difficult to design and build complex hardware, and because hardware
does not have many catastrophic failure modes. Additionally, hardware
is expensive and cannot easily be modified, so there is a much greater
incentive to get it right.



Oh really? How many circuit boards have you designed? I have designed
quite a few, and have done the embedded firmware for them as well.
Hardware designs can have bugs just as can software, they are just of a
different nature. Hardware bugs can be much harder to find and fix
than software becasue they are often the results of multiple variables
(circuit/environment/input conditions/power quality etc.). By
comparison, software is at least constrained to a specific set of
instructions and syntax. Plenty of hardware designs have bugs that
slip past initial testing and don't get found until the right corner
condition is hit...

I agree. I started life as a computer scientist (CS degree) and then
went back to school a few years later for my EE degree. Both areas have
their challenges. The advantage in circuit design is that the tools are
much more advanced as is the underlying theory. The software
community has a long way to go in this arena. The disadvantage in
circuit design is that circuits don't always behave the same way.
Changes in temperature can introduce problems for example as can static
electricity. A circuit can work fine one day and not the next.
Software works the same every day. All software problems are design
errors, whereas hardware has both design and fabrication errors as well
as material degradation over time. None of these affect software.

I'm not going to say either area is easier or harder than the other as
both have their challenges.


Matt

Matt Whiting wrote:
wrote:
Hardware testing is much more straightforward, because it is much more
difficult to design and build complex hardware, and because hardware
does not have many catastrophic failure modes. Additionally, hardware
is expensive and cannot easily be modified, so there is a much greater
incentive to get it right.



Oh really? How many circuit boards have you designed? I have designed
quite a few, and have done the embedded firmware for them as well.
Hardware designs can have bugs just as can software, they are just of a
different nature. Hardware bugs can be much harder to find and fix
than software becasue they are often the results of multiple variables
(circuit/environment/input conditions/power quality etc.). By
comparison, software is at least constrained to a specific set of
instructions and syntax. Plenty of hardware designs have bugs that
slip past initial testing and don't get found until the right corner
condition is hit...

I agree. I started life as a computer scientist (CS degree) and then
went back to school a few years later for my EE degree. Both areas have
their challenges. The advantage in circuit design is that the tools are
much more advanced as is the underlying theory. The software community
has a long way to go in this arena. The disadvantage in circuit design
is that circuits don't always behave the same way. Changes in
temperature can introduce problems for example as can static
electricity. A circuit can work fine one day and not the next. Software
works the same every day. All software problems are design errors,
whereas hardware has both design and fabrication errors as well as
material degradation over time. None of these affect software.

I'm not going to say either area is easier or harder than the other as
both have their challenges.


Matt
Actually;
software can have coding ( fabrication ) errors as well as design
errors. Just like in the hardware design, they don't become apparent
until just the right set of inputs is received, then boom.

John Theune wrote:
Matt Whiting wrote:

wrote:

Hardware testing is much more straightforward, because it is much more
difficult to design and build complex hardware, and because hardware
does not have many catastrophic failure modes. Additionally, hardware
is expensive and cannot easily be modified, so there is a much greater
incentive to get it right.



Oh really? How many circuit boards have you designed? I have designed
quite a few, and have done the embedded firmware for them as well.
Hardware designs can have bugs just as can software, they are just of a
different nature. Hardware bugs can be much harder to find and fix
than software becasue they are often the results of multiple variables
(circuit/environment/input conditions/power quality etc.). By
comparison, software is at least constrained to a specific set of
instructions and syntax. Plenty of hardware designs have bugs that
slip past initial testing and don't get found until the right corner
condition is hit...


I agree. I started life as a computer scientist (CS degree) and then
went back to school a few years later for my EE degree. Both areas
have their challenges. The advantage in circuit design is that the
tools are much more advanced as is the underlying theory. The
software community has a long way to go in this arena. The
disadvantage in circuit design is that circuits don't always behave
the same way. Changes in temperature can introduce problems for
example as can static electricity. A circuit can work fine one day
and not the next. Software works the same every day. All software
problems are design errors, whereas hardware has both design and
fabrication errors as well as material degradation over time. None of
these affect software.

I'm not going to say either area is easier or harder than the other as
both have their challenges.


Matt

Actually;
software can have coding ( fabrication ) errors as well as design
errors. Just like in the hardware design, they don't become apparent
until just the right set of inputs is received, then boom.

I don't consider coding to be fabrication, but I probably should have
used the term manufacturing. The point is that subsequent units of
"production" of software aren't assembled in the way that most
electronic or mechanical devices are assembled and thus don't share that
failure mode. I consider coding to be more equivalent to engineering
prototypes in the electronic and mechanical worlds. Stamping out CD is
the equivalent to manufacturing and stamping out CDs is less error prone
than assembling a complex circuit board or mechanical device.


Matt

In article , Matt Whiting
wrote:

All software problems are design errors

Um, no. Coding errors are fabrication errors. Errors introduced by faulty
development tools are also fabrication errors.

Production errors could be caused by a bad copy of the software executable.

And then there are requirements errors not covered by design errors. That is,
the wrong requirements given to the software weenies.

--
Bob Noel
Looking for a sig the
lawyers will hate

Skywise wrote in
:

Mxsmanic wrote in
:

Snipola
I already know too much about them, which is why I worry. The people
who recklessly put them into everything need to learn a lot more about
how and why they fail.

Computers are infallible.

Brian

Well, it's good to see my statement got the kind of discussion I
was hoping for.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html
Sed quis custodiet ipsos Custodes?