| The dismal science|
Planned obsolescence is an industrial/mercantile tactic that involves supplying products (and sometimes services) that have a shorter lifespan than could be engineered for the same or a lower price. Obviously, this keeps businesses moving by supplying new things constantly, and avoids the usual pitfalls like market saturation - because you can't saturate a market if your product doesn't last long enough.
Short lived products
Sometimes subcomponents are built poorly, to ensure revenue from parts sales and service calls. The classic example of this were starters and alternators on American cars, which would corrode and die with regularity. They were easy to stock, easy to install, and easy to rebuild. Another common example is the incandescent light bulb, which can easily be manufactured to last several decades - indeed one of the big savings from buying incandescent energy-saving bulbs is that you replace them less often so don't buy new ones. Entire products are also built to endure less time than a consumer might expect. For instance, a washing machine could easily be useful and efficient for several decades, perhaps with minor service. But if they only last ten years (
Collusion cooperation may be required as you might run into competition problems when a competitor's product lasts 11 years), people will get used to buying new ones every decade. An adjunct to this method is to simply stop providing parts (or repair information) after a few years of service life.
A variant is whether products are designed to be easily maintained and repaired allowing their lifestyle to be extended, or impossible to fix so they must be thrown out and replaced. Early cars could often be fixed with a few simple tools and cheap parts, but today, you may need highly complex electronic equipment to connect with engine electronics, and a vast range of strange spanners and star-shaped screwdrivers to unscrew anything, even before you have to buy replacement components. A contemporary example is mobile phones and laptops, which formerly had an easily-replaceable battery due to the fact that batteries lose their capacity more quickly than other parts fail; however today many have sealed-in batteries guarded with proprietary encryption.
A slightly more sophisticated technique that has been developed is fashion. We are all familiar with the constant churn in colors and styles in the fashion industry, and to an extent in the automobile industry (would you like fins with that?), but this tactic can be used for almost anything. If it ain't cool no more, you gotta buy a new one!
In the world of office software and operating systems, perfectly good products are rendered obsolete by the practice of issuing "upgrades" which add a few bells and whistles here and there, and announcing that technical support for the older version will sunset by a certain date. Many people consider Windows 8 to be a downgrade from Windows 7 (you're not a proper computer nerd unless you say that
Windows 3.1 MS-DOS 5 was the pinnacle of disk-based operating systems), yet the same tactic of cutting off support to encourage migration to the crappier version applies. Windows 10 seemed to have bucked that particular trend, though the sales numbers aren't promising.
You get what you pay for
This should be distinguished from building shoddier products to meet a targeted price point. Of course, because bitching about stuff you bought is so much fun, it never actually is.