The situation where professional writing is performed. Includes the people involved (i.e., the sender and the receiver), relationship between the people involved in the communication, time and place, and, some possible interference.
Message
The context of your document. It includes the main topic and the details that support it. These details may be in the form of facts, statistics, testimonies, and observation.
Language
The channel to convey the message. It can either be visual or textual, formal or informal, verbal and non-verbal. Note that you need to follow the standard form and usage of language in professional writing.
Purpose
The reason or motive that you have when communicating. It also helps you determine the reactions you want to elicit from your target audience. In the context of professional and academic writing, your two general purposes are to inform and to persuade.
Inform
To make the audience understand a concept
Persuade
To influence the readers to change their attitudes or actions
Audience
The receiver of the message. It can either be primary, the direct receiver of the document and the secondary or the indirect receiver of the message.
Product
The output that you intend to produce after considering all the other components.