The “Industry Expertise Only” Option
To enable this option, go to the New Game Settings menu and open the Experimental DLC page, then select the New Game Rules tab.

When this option is enabled, persons will no longer possess general skills such as retailing or manufacturing. Instead, they will specialize in a specific product class. Their industry-specific expertise will enhance not only the R&D units dedicated to their particular product class but also the manufacturing, purchasing, and sales units focused on that same product class.
For firms managed by a person with industry expertise:
1) Each expertise point the person has in a product class increases the R&D performance of that class by 1%.
2) When upgrading a manufacturing unit in that product class to a higher-level technology, the unit’s level will remain unchanged.
3) Manufacturing, purchasing, and sales units focused on that product class will have higher levels.
Example:
If a person has industry expertise in the Computer product class, all manufacturing, purchasing, and sales units related to Computer products will receive increased unit levels. This grants the character a strong competitive edge in both producing and selling computers.