OTRS ( Open-source Ticket Request System ) - open source software that allows a company or organization to support the so-called ticketing system (also known as Helpdesk or Service Desk ). Such a system makes it possible to assign " tickets " to communication with internal (eg company employees) and external customers (eg owners of the company's products). Communication may concern, inter alia, questions and complaints from users, requests for help, reports of failures, etc.

Source:

https://pl.wikipedia.org/wiki/OTRS