Today's entry in Pragmatic Marketing's product management weblog links to an article by Jacques Murphy called "Software Design: Seeing vs. Thinking". The article raises important issues that product designers face when balancing the needs of simplicity and flexibility.
However, the article seems to assume that product managers play a direct part in designing the products they manage. I firmly believe that product design lies outside the scope of a product manager's responsibilities.
A product manager determines the requirements for a product, but not its design. Thus a product manager specifies what a product should do (functional requirements). She also places constraints on the product's behavior (nonfunctional requirements), such as how easy to use it should be. But placing constraints on a product's behavior does not mean specifying the product's design.
A product manager is uniquely qualified to learn what the market demands and translate this knowledge into product requirements. But only an ergonomist or user interface expert is qualified to design a product that satisfies these requirements. How many product managers are trained in user interface design?