A conversation interface system provides remote access to manufacturing operation information using plain language message exchange. A cloud-based conversation interface service is exposed to an instant messaging application, and receives plain language queries from via the instant messaging application's interface requesting information relating to one or more industrial systems. The cloud-based system synchronizes the queries to one or more on-premise conversation interface agent devices residing at one or more plant facilities. The on-premise agent devices translate the queries and apply the translated queries to local sources of manufacturing operation data. The on-premise agent devices then generate and return response messages based on the retrieved information, and the cloud-based system directs the response messages the originators of the queries via the instant messaging interface.