Last week the word of the week, jolly, was very positively connoted. This week we have just the opposite. The word failed is negatively connoted. If something were to not work, it would be considered failed. A plan, or a machine could fail. Also, it could mean someone is not good at what they do, which in my opinion, should never be used in that context. The word failed is heavily negatively connoted.
The word failed symbolizes the frustration that comes when something were to not work. This is often a case of a failed plan. If a plan were not effective enough, you would consider it to be a failed plan. Sometimes a failed plan is very costly, other times it is just that it does not work the first time, and it needs to be tweaked into a new idea.
Machinery is described as failed when it is broken. Whether overheated, missing a bolt, or any other of the seemingly endless causes of a machine malfunctioning, failed could describe any technical issue. To tie this in with my previous example, a failed design on a machine could amount to a failed machine.
Failed could also be used to describe a person. If they are not good at what they do, one might say they failed. Maybe they are the failed designer of a failed machine. Sometimes it is friends joking around. Other times, it is used as a rude way to tell someone that they need to find something that they are better at. I personally hate it when people insult other people. I feel like it is easy enough to keep it in your head rather than blurt it out to embarrass someone.
Failed is an interesting word, but can be offensive if used in the wrong context. If you find yourself using the word, please make sure it will not offend anyone.