CTQ means ‘Critical To Quality‘ and you can actually use that methodology for just about anything that you want to talk about in terms of quality, but here we’re focusing on CTQ components for electrical and mechanical products specifically. We’ll examine some good examples of critical to quality components and how component engineers are recommended for managing their quality, and some of the key tasks they handle for you to do so.
What are CTQ components? (Examples)
Not every component in your product is critical to its quality. It’s fair to say that in some cases the product may function correctly even if the component is missing or inoperative, however with some components that’s absolutely not the case and it’s those we’re looking at.
All of the following can be considered CTQ components: an LCD or display is one of the most important components in any electronic product requiring a ‘screen’ of some kind, but there are also batteries, PCBAs, connectors, microprocessors, and ICs. You can also include just about any custom parts required specifically by your product such as covers or housings. As you can imagine, if these types of components aren’t working properly or are of poor quality this will strongly impact the product and consumer’s experience.
For example, in the case of the display, if it goes out you’re not going to be able to see the instructions or communicate on, say, your cell phone or tablet. The same story with the battery, as then you won’t have any power for your product.
If there are any kinds of issues with PCBA the components just won’t function properly and if there are any issues with the connectivity either you’re not going to connect or you’re not going to have any power. Microchips basically allow your product to function, so any issues with those are a killer.
As you can see, these CTQ components have such an effect on the success of your product that you need to manage their quality or else you’ll never know if they’re going to meet your performance and specification requirements.
Why component engineers are key to managing CTQ component quality?
Every large company that actually designs and builds really major products has a component engineering department or at least a materials management department that focuses on the management of CTQ components among other things. Component engineers are actually quality and reliability engineers and they ensure that the components designed for the product are actually going to be high enough quality, and meet your and the end user’s reliability, design, and performance requirements.
Not every business can set up a department like this, especially SMEs, but that doesn’t mean that you can’t manage CTQ component quality in-house. Budget-permitting, we suggest that you should have a component engineer as a part of your team.
That’s because they can handle so many time-consuming and complicated tasks that make up managing CTQ part quality and are crucial to the company’s bottom line. The following tasks are what would typically be done, especially for an electronic or mechanical product’s CTQ parts:
Managing the parts database
Component engineers not only take care of selecting the best (highest quality and reliability) components but also manage and organize your company’s parts database. For example, you have 100 parts for this project, another 200 parts for another, and a further 150 for another project. There will perhaps be a lot of common parts among these, and if you don’t have a component engineer checking the parts database looking for situations like this, it’s possible that purchasing (who don’t have an engineer’s eye and may not see common parts appearing between projects) might buy the same parts for each project from three different vendors!
This presents quality issues because you don’t know what’s going to happen with the three of them. Which one’s going to work or fail and which one is high quality or not? One thing is for sure, though, you’re going to pay a high price for these components because the volumes are going to be low when bought in three separate batches.
Component engineers will tally up the common parts and place a larger order from just one supplier in order to save on costs.
Performing component-level testing
As well as managing the parts database they often test those components, too, doing component-level testing right on the board or in the lab on each part alone. By doing so they can cross-check the component’s data sheet with how it actually performs in reality. There are a lot of tests that engineers could do:
- Test to failure within the design just to see if the component is meeting your performance parameters and data sheet requirements.
- Limit testing such as pushing the component over current and over voltage.
- Drop testing the component to see how durable it is in real-world conditions (if a product could be dropped).
Typically you’ll choose the critical tests that are going to add value for you to determine the quality of that component.
Doing supplier audits
A supplier audit is really critical because it allows you to find out a great deal of information about the component in terms of quality, volumes, testing documentation, and whether or not all of that adheres to, say, an ISO standard. You’ll quickly get an idea of whether you’re dealing with a world-class or second-tier supplier.
During the supplier audit, your component engineer would coordinate with perhaps a design and quality engineer, supply chain staff, and reliability engineers, too, if possible. They would all travel to the supplier’s site and perform a very detailed audit of the facilities and manufacturing and score the supplier based on their findings. They might compare two suppliers who produce the same components and record the audit results in your approved supplier list (or AVL – approved vendor list) which is also a great reference resource for when the design engineer needs a part quickly. All they need to do is just check that list of approved vendors, find one for that part, and then go to their website or download their datasheet to check the information and then they’re ready to order the part immediately.
Evaluating suppliers’ quality documentation
Some companies purchase sample parts from the supplier and send them to a third-party lab, instructing them to make sure that it meets certain requirements, such as a frequency, voltage, or current level, or that it’s not going to fail at a certain temperature for a period of 500 hours, for example.
However, a lot of companies that don’t have the budget to use a test lab or the time or capability to test some of these components in-house request quality and reliability testing documentation from the supplier. This may be the latest qualification test report for their component which every well-organized supplier should typically have available.
The qualification report should be detailed and have been done recently. It will show the number of samples that were tested, how they evaluated the results, if the results were passes or failures, and how a test failure was corrected (if there was one). The component engineer will perform a kind of technical audit on the documentation in order to review the data with a technical eye so you don’t take the supplier’s results as gospel. After all, would you stake your livelihood on the veracity or accuracy of their results? Worst case, if the results aren’t right you could end up selling a product that’s unsafe and could cause consumers to be harmed. If something worrying is found by the engineer, further information can be requested or the budget for testing can be sanctioned in this case.
Doing component pilot runs
Doing a pilot run for CTQ components is important. You would basically take a batch of samples of the component, such as an IC reel, and run it on the next build making sure that everyone knows that it’s being used at this position on the PCB for the purpose of testing and our goal is to understand its performance. Some of these limited boards would be given to R&D test engineers who would test the parameters of these components in isolation (not the full product) with respect to seeing if that specific IC is actually performing according to expectation among others that connect to it.
In this way, a component pilot run could be a very useful and low-cost alternative to component-level testing because you’re not testing one component alone, rather you’re testing maybe hundreds at once as they’re connected, but only in, say, one system, not the full product. If you don’t want to spend time and money on testing, you might just run a pilot run like this and if all of the components perform well and you get a large sample size of, say, 500 boards, 500 Parts, and 500 PCBs with that one part in them, then you’re good to go.
Doing engineering test to failure evaluation
Engineering evaluation is helpful when you have a particular custom part that engineers designed for you. The component engineer really needs to test to see if what was ordered actually meets your specification and performance requirements.
Let’s take the example of some rubber bands. They’re supposed to be elastic up to 10 centimeters, but, after being pulled to that length they all broke. Obviously, they didn’t meet the requirement.
Similarly, in engineering, you have parts that you order, and the component engineer will put them back in your breadboard or prototype, and then test them, sometimes even to the limit. This might be by performing reliability tests such as putting them in the temperature oven, exposing them to heat and cold, maybe over current and over voltage, vibration, and so on. This will help make sure that the parts actually meet the basic requirements that you have in mind.
What I’ve mentioned here are really typical examples of what a Critical to Quality components could be in an electronic product, but for products in different industries, your list of critical components could grow, for example, in the Auto industry where there may be a very large number of them. Brakes and lights, for instance, are critical to quality and you just cannot accept them failing.
Conclusion
In conclusion, it is very advisable for companies who have the budget to hire at least one component engineer or even set up an entire component engineering department if you have high-volume manufacturing. Their role is to de-risk the critical components going into the product and reduce the issues related to them should they fail. Most likely you will then benefit from a lower return rate and therefore enjoy cost savings, better customer satisfaction, and better performing and quality product.
As far as deciding which components could be critical, a component engineer should put together a team of engineers, designers from different projects and supply chain, quality, and reliability team members and then brainstorm which are considered CTQ with respect to your specific product. They’ll list those components and then start allocating tasks, for example, they might require that one particular component can be tested by doing just a pilot run, for another, a supplier audit will be needed, and one might only need a quick engineering check, and finally, another might not need any action to check its quality as it’s already from an approved supplier.
Ultimately they all decide what those CTQ components are and then the smartest, fastest, and cheapest way to qualify them as acceptable in terms of making sure that they still meet your manufacturing, performance, specification, quality, reliability, and testing requirements.
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As ever, if you have any questions about this topic, sourcing suppliers and components, and manufacturing your product, let us know by commenting or contacting us.
