Professional dishwashers are normally gravity drain.
If the drain outlet of your appliance is high or positioned far from the installation point, a drain pump will help drain water properly. Moreover, a drain pump will allow a full bleed of the wash tank of your appliance once the work session is over, simply by pressing a single button.
Attention! The waste outlet hose should be adapted to the distance between the appliance and the drain point at the wall, allowing the possibility of taking the appliance out from its place.
Teikos suggests that you ask your supplier for advice and evaluation of the specific requirements of your site.