If I am an expert and would like to expand my knowledge in one particular area (let`s take Process Analysis as an example) the best way to stay up-to-date is to subscribe to the Process Analysis category. 

On the top navigation, click on the Community to expand the menu. That way you see all areas where the community members can ask questions and conduct discussions.

Under Product Q&A section, there are product specific areas (categories) you can subscribe to:

When you subscribe we will email you when there is a new post in the category.

Remember to set up your Notifications settings. More in How to set own profile preferences?

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