A quality translation demonstrates required accuracy and fluency for the audience and purpose and complies with all other negotiated specifications, taking into account end-user needs. Reference: Dr Alan Melby and Arle Lommel, 2013.
Quality assurance (QA) is the set of processes required to ensure confidence and quality in a given project, as a whole or as a specific individual task. The accuracy and purpose of the translation should meet expected levels of performance, such as an acceptable degree of consistency, completeness and style.
Quality control procedures in the translation industry include the correct methodology for certain situations that are planned or occur in the course of a project in order to meet requirements. This includes processes that ensure the functional quality of the supporting files such as bilingual translation files, translation memory files and exchange formats.
The Translation Centre for the Bodies of the European Union (CdT) describe quality as accuracy, consistency, completeness, style, register, formatting, respect of the instructions provided and of the deadline, etc.
Multidimensional Quality Metrics: A Flexible System for Assessing Translation Quality Multidimensional quality metrics Framework, QTLaunchPad Project