What makes a good infrastructure design? The answer could be summarized by saying that it includes the following qualities:

• Availability
• Manageability

• Performance
• Recoverability
• Security

The infrastructure design qualities, also called design characteristics, should be incorporated into every enterprise design. We saw these when we described them earlier in this chapter as nonfunctional requirements. That is to say, they describe how a design should work. In addition to meeting the customer's requirements and constraints, it may not be a good design overall if the design qualities were not considered.

Throughout the design process, it's a good idea to understand how each design decision impacts the infrastructure design qualities. Continually ask yourself: if the design qualities are my end goal, how does this design decision affect them?