A translation engine is software that performs the work defined in individual transformation maps.

The transformation engines that power transformation maps are typically defined as “single-pass” or “multiple-pass” engines.  Single-pass engines are faster than multiple-pass engines because documents are directly translated from source formats to destination formats, but single-pass engines often require more manual setup and are harder to integrate and extend than multiple-pass engines.  Multiple-pass engines use an intermediate format (usually XML) between the source and destination formats; this makes them slower than single-pass engines but often eases interoperability between systems.

BEST PRACTICE: Your decision to use a single- or multiple-pass map transformation engine should be predicated first on performance, then on interoperability.  (It won’t matter how interoperable your deployment is if it can’t keep up with your traffic.)    However, the ever-increasing speed of computers and more common use of parallel, coordinated systems is gradually tilting the file transfer industry in favor of multiple-pass transformation engines.