If you think of the product as a service, then the separate parts make no sense - the point of a product is to offer great experiences to its owner, which means that it offers a service. And that experience, that service, comprises the totality of its parts: The whole is indeed made up of all of the parts. The real value of a product consists of far more than the product's components.
Donald A. NormanWhat makes something simple or complex? It's not the number of dials or controls or how many features it has: It is whether the person using the device has a good conceptual model of how it operates.
Donald A. NormanToo many companies believe that all they must do is provide a 'neat' technology or some 'cool' product or, sometimes, just good, solid engineering. Nope. All of those are desirable (and solid engineering is a must), but there is much more to a successful product than that: understanding how the product is to be used, design, engineering, positioning, marketing, branding-all matter. It requires designing the Total User Experience.
Donald A. NormanWe delude ourselves if we believe that skilled behavior is easy, that it can come about without effort. We forget the years of tuning, of learning and practice it takes to be skilled at even the most fundamental of human activities: eating, walking, talking, reading, and writing. It is tempting to want instant gratification - immediate expert performance and experiential pleasure - but the truth is that this primarily occurs only after considerable amounts of accretion and tuning.
Donald A. NormanProducts were once designed for the functions they performed. But when all companies can make products that perform their functions equally well, the distinctive advantage goes to those who provide pleasure and enjoyment while maintaining the power. If functions are equated with cognition, pleasure is equated with emotion; today we want products that appeal to both cognition and emotion.
Donald A. Norman