RSM Simplified: Optimizing Processes using Response Surface Methods for Design of Experiments

"We make trade-offs in every solution, trying to minimize the pain and maximize efficiency, but never entirely ridding ourselves of the pain and never quite building the perfect system."
MICHAEL F. MADDOX (COMPUTER PROGRAMMER)
Up until now, so as not to complicate matters, we've concentrated only on one response per experiment. However, any research done for practical purposes invariably focuses on multiple responses. We will now provide tools to deal with the inevitable trade-offs that must be made when dealing with multiple responses from designed experiments.
In the mid-1970s, Miller Brewing Company introduced its Lite beer brand with the advertising tagline "less-filling/tastes-great." Whether they actually accomplished this difficult trade-off may be a matter of debate, but it struck a chord with American beer drinkers. The Miller ads promoted the view that with proper technology, a sweet spot can be found where all customer needs are met.
By the late 1990s, light beers accounted for over one-third of all beers brewed in the USA. Miller, Budweiser, and Coors led production in this market segment, which amounted to nearly 80 million barrels of beer. Dr. Joseph L. Owades, founder of The Center for Brewing Studies in Sonoma, California, came up with the idea for a low-calorie beer when he worked at Rheingold a New York brewer. He investigated why some adults did not drink beer (many people don't!). The answers he got were twofold:
"I don't like the way beer tastes."