When thinking about quality control, consistency in the quality and taste of food always comes to mind.
The most basic version of this would be to write down a recipe. That way someone can follow the recipe. However, when writing the recipe there are still variables. This can be seen in baking where often the most consistent recipes are measured in weight rather than volume. This usually separates professionals from amateurs.
Past the weight vs. volume argument and figuring out which measurements of the recipe makes things most consistent, there are still flavor inconsistencies. What if this brown sugar has more molasses contained than the last batch we had? That could change the flavor of the cookies.
The last defense of quality control in the kitchen is someone with a great palette who can adjust to bring each and every batch into consistent levels with the previous. This level of quality control isn’t nearly as scalable. Teaching someone to read a recipe, pretty easy. Teaching someone to zero out a scale and measure exactly, pretty easy. Teaching someone to use their palette to adjust the recipe when it tastes like the molasses content was low, or the salt tasted more minerally than usual or other small imperceptibilities, isn’t very scalable. It’s a skill and a talent.
In your world, in your organization there are probably people controlling the quality of goods and services in ways that you’ve never thought about. Ways that you couldn’t possibly train them to because it’s an ingrained talent. This might be making people enjoy a training class. This might be making customers enjoy a conversation with your organization. This might be a person who does all sorts of double checking after implementing new software. The highest level of quality control is an art, and if you found a great artist, it’s worth letting them know how much they are appreciated.