Planned Obsolescence

The built-in defect of a power supply?

Planned obsolescence or built-in obsolescence in industrial design and economics is a policy of planning or designing a product with an artificially limited useful life, so it will become obsolete, that is, unfashionable or no longer functional after a certain period of time.
((source: Bulow, Jeremy (November 1986). "An Economic Theory of Planned Obsolescence". The Quarterly Journal of Economics (New York: John Wiley & Sons, Inc.) 101 (4): 729–749. doi:10.2307/1884176. Retrieved April 9, 2013) reference: www.wikipedia.org)

By the appearance of this wording many end customers were made insecure or felt their personal subjective opinion to be confirmed that modern products simply do not last as long as they did in the past. The fact that even a term had been created to describe that effect which they “felt”, has obviously been understood as the long-awaited confirmation that the industry lets their products get defect with intent in order to increase the sale of new products.

Frankly speaking, this idea is not without a certain degree of logic and many experiences with new products seem to prove true at first sight.

But what is the real situation of new products and their durability? In this text, we will explain it on the basis of the omnipresent product power supply such like FRIWO produces millions of pieces which are used worldwide in the most divergent conditions. 

In fact, how do we define or measure durability (reliability)?

For technical evaluations there is the complex term of „MTBF“ (Mean Time Between Failures, seldom called „Useful Service Life“). Roughly speaking, it describes the statistical probability that a product fails. It is indicated in hours. If a product has a MTBF of 100 hours, this does not automatically mean that it has a general lifetime of 100 hours; it means that there is a high probability that this product will not fail within 100 hours. However, a failure cannot completely be excluded before the end of this period; early failures can happen due to faulty components or potential processing faults. After these mentioned 100 hours ageing effects occur which lead to an increased failure rate.
If we consider 100 identical units with a MTBF of 100 hours, in theory it would be possible that one unit fails every hour. The MTBF time indication has to be taken as a statistic value concerning the complete amount of units considered.
However, in general it is right to say that a unit type with a higher MTBF has a longer lifetime. Of course, the value of 100 hours has been chosen as a simple example and is much too low for a real power supply: A MTBF of 100,000 hours and higher is quite common (it is not a rare exception) FRIWO’s catalogue-listed units usually have a MTBF of 200,000 hours, following our own quality standards.

How can MTBF be calculated?

The calculation of MTBF is firmly defined by several standards, such as IEC 6209 for example. This standard has been derived from Siemens in-house standard SN29500. Among others, it serves as a basis for professional calculation software, such as program WINDCHILL by PTC (formerly Relex). Different basic standards can be included in this software program and resulting from this, the calculation mode will be executed according to the particular standard.
Without MTBF calculation, complex machines or technical devices such as satellites or commercial aircrafts could not be evaluated concerning reliability over all components nowadays. Some time ago, the military sector has also realised this necessity and created its own standards. They reflect the specific requirements and enable the definition of durability and reliability concerning military products. We would like to mention the US handbook HDBK-217, which was no longer updated after issue F.

Consumer vs. Professional and reliability of products

After a short excursus to the statistic values of durability, we now focus on its practical implementation for different product classes. If a high MTBF rate shall be reached (like mentioned before), components must not always run at their full capacity even if their specification would allow for. Components generally last longer, if they only work at partial capacity.
As an example, we would like to take capacitors in electronic devices – this topic is discussed very often: Especially the bigger ones, filled with electrolyte, can dry-out easily. This is why they should only be operated as cool as possible. According to the so-called Arrhenius-formula (Svante Arrhenius 1859-1927: Swedish physicist), the expected lifetime of an electrolytic capacitor is doubled every time the operating temperature is reduced by 10°C.
Let’s assume that a capacitor offers an operating time of 2,000 hours at its maximum operating temperature. Now, if it can be made sure that the maximum operating temperature will always be 10°C lower, the expected lifetime of the capacitor would rise to 4,000 hours. If the capacitor would be the weakest part within the power supply, the lifetime at a 10°C cooler operating temperature would double statistically (if all other components could be disregarded). But, if the operating temperature cannot be reduced, components allowing higher operating temperatures have to be used to increase MTBF. In our example this could be a capacitor with 5,000 or even 10,000 operating hours. However, such components are 4 to 10 times more expensive, so for economic reasons they will only be chosen if these higher costs can be transferred to the consumer sales price of the product and still create a corresponding financial yield. In return, a customer only buys a more expensive product if it definitely offers him advantages and a considerable benefit compared to cheaper ones.

On the other hand, to be honest, who had asked for the durability before his latest purchase of an electronic product? Only a few do this - and pursuing this idea - if you ask, how many customers have taken a closer look at the attached portable or built-in power supply, their number would fall close to zero. This topic is not within the customer’s focus and therefore, a lot of companies try to save money by attaching power supplies to their products which barely meet the minimum standards required - although power supplies are important accessories of routers, entertainment electronics, mobile phones, and so on. Exactly this is the weak point which finally led to the accusation, power supply manufacturers willfully include soft spots into their products in order to increase their sales.
Professionals have been paying attention to a high MTBF of a power supply and this rate is an obligational part of the unit’s specification. Meanwhile, it went one step further and a certain minimum lifetime of 5,000 to 10,000 hours for all capacitors inside a unit is demanded.

Usually, the end customer does not have such a profound technical background to consider the above mentioned aspects or to question them during the buying process. A principle approach for higher product durability and by consequence sustainable avoidance of electronic waste would surely be legal demands for minimum MTBF values of power supplies and other electronic devices. By this means, all suppliers would be forced to implement better quality components. This would lead to an increased demand for such components and their production prices would go down due to economics of scale. The add-on cost for the end user would be put into perspective by a better durability of products.

Conclusion:

There is no „built-in obsolescence” to increase the manufacturer’s turnover! But in deed, there is a non-optimal durability due to market constraints which concerns each and every manufacturer who uses electronic components.
A solution to this conflict can only be achieved by the critical customer himself or general political directives - best case being valid on European level.