These aspects are also important for long term or frequent projects where consistency must be maintained over time. Translation agencies work with many networks of translators, proofreaders and editors to accomplish your translation goals. A translator can translate a standard number of words per hour. Knowing the number of words to be translated allows a translator to schedule a document and meet delivery requirements. Technical documents are usually more expensive to translate because they are more complex and therefore take longer to translate.
Translation is a very subjective field.
There are many ways to say the same thing. It is similar to reading a book. Some may thoroughly enjoy a book while others find the words unentertaining. Providing a glossary of words you would like used allows you to keep control over your document. Of course, bad translations exist.