Does a translation need to be updated every few years? Perhaps your product has a user manual that was translated over ten years ago… does that mean that the translation is “old?” A translation for a user manual can generally last as long as the device does. If no user interface has changed or the workings of the device haven’t changed at all, why should the instructions to use that device change? Indeed, as long as the original written instructions for use remain the same, the translations of the instructions won’t need any revision.
Nonetheless, review and revision of translations is always important. Whenever a new document is released, it is the translator’s duty to review the unchanged text alongside the new text to ensure that all text is appropriate for current use. With new emerging technology new terminology can emerge and languages may have established new ways of translating these words. It cannot be assumed a phrase will always be translated in the same way. Translators will check source text against the previous translations to look for consistency but they sometimes find the old text should be changed. Often when they report that a previous translation should be changed, it is because modern conventions have changed. Perhaps old terminology has fallen out of favor and newer terms are preferred. It would be convenient if language were static and could consistently relied upon but adhering to modern usage is always important.
So, in general, your translation will have “staying power” but should always be reviewed to ensure that it is still relevant. As long as your device is not “ancient,” your translation shouldn’t be either.