ConfigurabilityAn Element of Usability

The primary reason to care about configurability, which is a dimension of overall usability, is cost. Difficult-to-configure systems

• Are harder to use, increasing operating costs.

• Are harder to tune, resulting in lower actual and perceived performance, which can increase costs by forcing customers to do such things as purchase unnecessary hardware.

• Result in more calls to technical support, increasing technical support costs.

• Require more complex professional services, increasing direct costs to customers because professional services take longer than they should, and decreasing employee satisfaction because very few professional services people get excited about configuring a complex system.

• Increase overall customer frustration, putting you at a competitive disadvantage .

A related reason to make configuration easy is based on the architectural nature of the systems you're creating, which are increasingly built using modular approaches. Modular systems increase configuration requirementsa fact that becomes increasingly true in architectures based on Web services. Without a strong commitment to easy configuration, you're going to see configuration costs increase over the life of your application. This is not a pleasant prospect.

You must architect ease of configuration. Doing so is in everyone's best interest. In terms of usability, configurability is having the right number of configuration parametersnot too many and not too fewand choosing parameters that affect the system in ways that are material to the user .