Translation services are a creative art that requires knowledge. More than simply switching out words in one language for another, translating texts requires a deep knowledge of both the source language and culture, as well as the target language and culture.
Machine translation is useful as it is quick and cost-efficient for content when the objective of the document translation and the content itself is appropriate for this type of translation service. But, even with the best machine translation software, it is beneficial to use a human professional translator to amend the output.
Machine translation is of greatest benefit when used judiciously evaluated, improved with post-editing and localizing done by a professional translator. For serious projects with unacceptable risk levels, use human translators start to finish.