A reliable and systematic method for updating circuit components that fall out of production?

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
Many of us find ourselves in a position where we are maintaining legacy electrical systems. Circuit boards that were designed 5, 10, or even 20 years ago can still be useful today, and are therefore still in production. The components that go on those boards, however, might not be reliably available over such long periods of time. Though this problem has been exasperated by the recent chip shortage, the problem has existed independently for as long as electronic products have been in production. Surely, after a hundred years of electronics engineering, there must be an established practice for mitigating these types of problems. Right?

Or is the hard way the only way? Is it necessary to understand every aspect of the design and how the components interact with the board as a whole? What if the boards were produced a decade ago by a TEAM of experienced engineers who are no longer around, and you are (hypothetically) a singular, inexperienced engineer trying to sustain such boards? Are there books written about this? Classes offered? Is there any reliable and systematic method that one can learn to better navigate this problem that we all face? Or is it just "work harder" and "hire more engineers" all the way down? Sorry for the rant, but any wisdom and/or advice will be greatly appreciated.
 

MaxHeadRoom

Joined Jul 18, 2013
25,466
I have had a similar experience where putting together a system designed with newly released components from well known manufacturers, International Rectifier for example.
The design is based and built around them, several months later the product is dropped?
Whether it did not meet the demand or other reasons, is never given.! :confused:
The upshot is, the design has to be re-worked, can be very frustrating!!
 

MrChips

Joined Oct 2, 2009
26,476
Are there books written about this? Classes offered? Is there any reliable and systematic method that one can learn to better navigate this problem that we all face?
I am going to hazard a guess that the answer is no.

Firstly, it depends on the scale of manufacturing and production. If you are one of the big guns you already own the semi-fab or have control on the supply chain.

If you are a small to medium OEM then you have to accept the risks and plan accordingly.

Let us narrow it down to the electronics OEM supply chain.
Furthermore, we will categorize the components into three groups, (1) discrete components, resistors, capacitors, inductors, semiconductors, (2) general purpose integrated circuits, e.g. digital logic, op-amps, comparators, voltage regulators, etc. (3) specialty ICs and components, e.g. MCUs, peripheral chips.

Strategies
#1 - Ensure there are multiple sources for all of the above.
#2 - The risk of supply chain disruption with group (1) is minimal. Create designs that allow flexibility in this area. Be prepared to redesign the circuit and PCB to accommodate revisions. This is a low cost risk.
#3 - For group (2) be prepared to accept substitutions and circuit and board revisions.
#4 - For group (3) maintain ample stock in-house for immediate and future needs. Be prepared to accept substitutions, circuit and board redesign and revisions. For example, it would be prudent to create code and code libraries to migrate from one MCU to another, even across different manufacturers. It is not difficult or costly to do versus the cost of higher prices and delayed deliveries.
 

Papabravo

Joined Feb 24, 2006
18,779
I have done disaster recovery for various clients over the years. In most cases the efforts were borderline useless since the first shortage led to subsequent shortages as the life cycle of all the components reached EOL. In retrospect it would have been cheaper and more efficient to start the redesign cycle earlier before the first crisis developed. This would also allow upgrades in requirements and performance. In the case of a marginal company, hanging on by the fingernails, this is a hard sell to the guy writing the checks.
 

dl324

Joined Mar 30, 2015
14,676
Welcome to AAC!
Circuit boards that were designed 5, 10, or even 20 years ago can still be useful today, and are therefore still in production. The components that go on those boards, however, might not be reliably available over such long periods of time.
Whenever components are about to become obsolete, manufacturers will provide notices and the cutoff dates for ordering parts. In some cases, there will be a drop-in replacement.

If your company has products that will be affected by parts becoming obsolete, you can either stockpile those parts or redesign the circuit to use different parts.
Is it necessary to understand every aspect of the design and how the components interact with the board as a whole? What if the boards were produced a decade ago by a TEAM of experienced engineers who are no longer around, and you are (hypothetically) a singular, inexperienced engineer trying to sustain such boards?
If your goal is only to be able to repair them, that's not as hard as trying to design them from scratch. When you get to the point where you understand why every part and value was selected, you'll be in a position to do a complete redesign. For partial redesigns, you only need a detailed understanding for the subcircuit in question.

Just repairing is more straightforward as long as you have schematics. You'd also need source code for any microcontrollers being used.
Are there books written about this? Classes offered?
What you learned in school should be sufficient If they taught you how to think versus doing things by rote.
 

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
There are no magic bullets. Engineering is difficult, and not meant to be easy.
Much of engineering is breaking large, otherwise impossible problems down into smaller, easier tasks that CAN be accomplished. Modular design comes to mind. There are many problems in engineering that would remain impossible, had it not been for clever engineers devising schemes to tackle such problems.
 

nsaspook

Joined Aug 27, 2009
9,983
If you have this responsibility you need to get ahead of the curve. If others are upgrading from your legacy electrical systems buy their stuff cheap for spares. Inventory and stock the major electromagnetic parts like compatible contractor, fans, motors, etc ... as these things failing will destroy otherwise good electronics. Use companies that can still customize things like power supplies, etc... Last but not least hire a few older guys that have been on this rodeo before to guide you.

Books? If you're new I'd recommend this for a start on the management and engineering side.

PXL_20220421_171122662.jpg
 

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
If you have this responsibility you need to get ahead of the curve. If others are upgrading from your legacy electrical systems buy their stuff cheap for spares. Inventory and stock the major electromagnetic parts like compatible contractor, fans, motors, etc ... as these things failing will destroy otherwise good electronics. Use companies that can still customize things like power supplies, etc... Last but not least hire a few older guys that have been on this rodeo before to guide you.

Books? If you're new I'd recommend this for a start on the management and engineering side.

View attachment 265555
THANK YOU!!! I was searching "sustainment engineering" and terms like that. MAINTENANCE engineering is the topic I need to investigate! Thank you thank you thank you.
 

Papabravo

Joined Feb 24, 2006
18,779
Much of engineering is breaking large, otherwise impossible problems down into smaller, easier tasks that CAN be accomplished. Modular design comes to mind. There are many problems in engineering that would remain impossible, had it not been for clever engineers devising schemes to tackle such problems.
It can be comforting to believe that the world is an ordered, rational system. The true situation is often otherwise.
 

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
It can be comforting to believe that the world is an ordered, rational system. The true situation is often otherwise.
You're not wrong, but your defeatist perspective is bumming me out. Look up Feynman diagrams if you're not already familiar with them; they're a terrific example of how impossibly complex systems can be simplified for analysis.
 

Papabravo

Joined Feb 24, 2006
18,779
What is defeatist about working in a field for decades and helping needy people with money solve their problems?
Color me confused.
 

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
There are no magic bullets. Engineering is difficult, and not meant to be easy.
You sure sound defeated to me. Engineering if FULL of magic bullets, just think about how many times Maxwell's Equations didn't have to be solved because the Lumped-Element Model was developed. Hell, I have a calculator app on my tablet that I paid $3 for, but it can calculate 200,000! out to 100 digits (the first seven are 1.420225x10^(973350) btw); if that isn't a magic bullet, what is? And don't even get me started on Wolfram Alpha, ADS, HyperLynx, et cetera et cetera. Engineering is primarily about making difficult things easier, your attitude is wrong.
 

nsaspook

Joined Aug 27, 2009
9,983
Engineering is much more than mathematical magic bullets. Most of the most vexing problems are out of the realm of math, like most of your decisions on how to keep Paleozoic Era electrical systems operational. It more about having a passion for understanding how things work and interact. Trig and calculus enable us to solve problems but first we need to know what problem to solve.
 
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Papabravo

Joined Feb 24, 2006
18,779
You sure sound defeated to me. Engineering if FULL of magic bullets, just think about how many times Maxwell's Equations didn't have to be solved because the Lumped-Element Model was developed. Hell, I have a calculator app on my tablet that I paid $3 for, but it can calculate 200,000! out to 100 digits (the first seven are 1.420225x10^(973350) btw); if that isn't a magic bullet, what is? And don't even get me started on Wolfram Alpha, ADS, HyperLynx, et cetera et cetera. Engineering is primarily about making difficult things easier, your attitude is wrong.
I certainly do not feel "defeated" after a successful career last half a century. How many people can say that?
 

MisterBill2

Joined Jan 23, 2018
12,396
Engineering requires not only knowing what to do with the individual parts, but in addition understanding exactly what the solution must do and provide. For servicing and repairing this involves understanding correctly and completely. what a system that was working actually did. Then it is a matter of understanding what it is NOT doing now, and that often quickly points to the problem very well.
For new designs first understand what must be achieved.
To avoid problems of parts becoming unavailable, the first stage is to use mature parts available from multiple manufacturers. This means that you ill never use the very latest, cutting edge, technology, and probably never suffer the pain of failed production yields making that latest processor have the 90 day lead time. Or not be available at all! (This is the reason that all the auto companies are suddenly unable to get their modules with the very latest processor technology.)
 

MisterBill2

Joined Jan 23, 2018
12,396
For ICs especially the digital kind, selecting those with the more common functions, even though it may require more packages, will allow substitutions when half of the suppliers are out of stock. Single sourced logic is OK If all that is needed can be obtained prior to the start of production. For linear devices there are times when only one supplier makes the part. Those times are dangerous, but on occasion unavoidable.
 

Thread Starter

Nate.Kilmer

Joined Apr 4, 2022
9
I certainly do not feel "defeated" after a successful career last half a century. How many people can say that?
Congratulations on being born a long time ago, you're clearly very proud of that. Could you take you're pessimism elsewhere? Some of the other people commenting here are actually trying to be helpful.
 
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