Dienstverpflichteter

21:24 Dec 1, 2018 

"Bei einem Arbeitsvertrag mit einer GmbH beispielsweise tritt die Gesellschaft als Dienstberechtigter auf, der Arbeitnehmer ist der Dienstverpflichtete ..."

https://www.unternehmerlexikon.de/dienstvertrag/

If I understand the explanations on the above website correctly, then an employee of a company may under certain circumstances also be a "Dienstverpflichteter" - but I'm not sure we'd call an employee a "service provider". It's my understanding that a service provider has to provide the agreed service; if he fails to do so, the customer can refuse to pay him. The service which the Managing Director referred to in the question is obliged to perform is to turn up for work. In other words, there's no agreed outcome (as there would be if someone was fitting a boiler, for example, or repairing your car).

18:48 Nov 30, 2018 

Geschäftsführer is managing director or chief executive, not chairman.