Our reliability expert, Andrew Amirnovin, recently discussed how to decide what kind of reliability testing your product needs for anyone starting from scratch who is unsure in this episode of the Sofeast podcast. Listen if you’d like to know more about reliability testing:
Here is a summary of some of the key sections…
What is product reliability?
Product reliability is where the product works as intended in normal conditions and usage by the consumer without breaking down for the required amount of time, such as its warranty period. Reliability can be achieved through designing the product to use rugged and durable materials and putting it through reliability testing which pushes the product to its limits to give you peace of mind that it will not fail in users’ hands.
Reliable products are beneficial for businesses for several reasons: improved customer satisfaction, great online reviews, lower warranty costs, fewer returns, and a better brand image being just a few.
The point should be made that reliability or durability is not the same as quality. Quality products are those that are exactly made to specification, but if their design makes them unreliable then they could still break down later on when in use.
What questions will a reliability engineer ask you in order to proceed?
If you’re working on devising which reliability testing is needed your reliability engineer will need to know these two things from you:
- What industry is the product in?
Different product industries demand varying levels of reliability for products. Consider medical devices, such as a pacemaker. There’s no margin for error here, the device must be totally reliable all of the time, as if it fails the patient may not survive. This is different to many everyday consumer products that are only expected to last, say, a couple of years or so before being replaced by the user with something new. For instance, a pair of headphones might only be used for a year or so, therefore it’s unlikely that a user will expect them to last for a decade! - What kind of product is it?
Various standards will apply to different products influencing the types of tests to be performed, the typical testing environment/s, and test equipment required. The engineer will start to make a reliability test plan including these items when they know the kind of product they’re dealing with.
Make clear your reliability needs for the product
The product’s reliability needs are based on what the consumer requires from the product. As the manufacturer you will gain this understanding from market research and user feedback, such as knowing that cellphone users will reasonably demand that the phone can survive a fall from being held, which. might be from approximately 1m in height, without breaking. The reliability engineer will then know that they need to incorporate a drop test into the reliability test plan that will assess the phone’s ability to survive drops from 1m or more.
While some idea of how the product needs to be reliable, such as its ability to withstand drops in the case of the cellphone, is helpful for the manufacturer, your reliability engineer will give you feedback on how realistic or necessary your reliability requirements are. In some cases, over-cautious manufacturers want to over-engineer and test products as they believe that it’s better to have an extremely rugged product that covers all bases. But for many consumer products, this just isn’t necessary and it will lead to much higher costs. For example, designing and testing that a bottle that will only hold boiling water to withstand temperatures of up to 200 degrees Celsius is overkill, as users can reasonably be expected never to add liquids at that heat. So, is this engineering and testing necessary? Your engineer will give you a wakeup call about this, so you only design products that do what is needed and not excessively beyond.
Examples of common reliability testing requirements for a typical consumer product (a smartwatch).
Let’s look at a typical electronic consumer device, a smartwatch. Here’s an example list of reliability testing requirements that other consumer electronics would probably also share:
- Functionality Testing: Do functions and features work as intended? This may be items like includes testing the display, buttons, connectivity, sensors, and GPS.
- Battery Life Testing: Battery performance in different environments and use case scenarios are tested.
- Durability & Reliability Tests: Is the device durable and likely to last as long as required? Drop test, vibration, water resistance, dust resistance, temperature and humidity testing, and more, will be done.
- Environmental Testing: Accelerated life testing, high and low temperature and cycle testing, HALT, and HASS testing can be used to assess the watch’s performance under different rather extreme environments.
After the tests are performed the results are analyzed and you will either be satisfied that the product is reliable enough, or you will see that there are failures that need to be fixed. This may mean altering the product’s design and then putting it through reliability testing again. Not every failure is bad. If a product fails under more extreme stress than it will reasonably be expected to withstand under normal daily use, you can probably take it as a good sign that it is durable enough.
Reliability is a good investment despite its cost
You need to find a balance between doing too much or too little design for reliability and reliability testing as it can be expensive.
Very durable products are more costly to make as they tend to use more complex designs, and more expensive components and go through very rigorous testing (which of course is also more costly).
On the other hand, an unreliable product may be cheaper and faster to bring to market but can this saving compare to the costs of:
- Warranty claims
- Reputational damage to your business
- Amazon pulling your products from its site due to too many bad reviews
- etc…
It’s unlikely, which is why we advise that it’s better to pay now to design and test a more reliable product, rather than paying later to clear up the huge mess unreliable products hitting the market will make.
To illustrate why spending money on reliability is a good investment, there’s an example of a $40 screw used in spacecraft that caused some debate in Congress in the USA. Some people were shocked that a single screw might cost so much and there was concern that the US taxpayer was being taken advantage of. But these were no ordinary screws. They had been engineered to withstand extremely high and low temperatures, the vacuum of space, solar radiation, and extreme stresses without failing. The consequence of their failure would be millions of dollars of lost equipment and/or lost human lives. Therefore, in that context, $40 seems more reasonable.
Conclusion
By understanding your product’s industry or niche, type, and the reliability level your customers will expect, you can design and test the product to be reliable enough.
Your reliability engineer will examine your product, and your customers’ requirements, and suggest design changes and a reliability test plan that will mean that your product is reliable or durable enough to avoid you having the stress of warranty claims, angry customers, and high repair costs without resulting in a product that is too expensive to manufacture and test and test due to be ‘over durable.’
Learn more about building reliability into your product
We recently made this webinar about creating reliable products that you may also enjoy…
