The presentation claims that architectural design plays a crucial role in system development as a first step in a process that turns a requirements specification into a working software and hardware system. As such, architectural design should follow a rigorous methodology - a science - rather than intuition - an art. Our basic premise is that requirements in information systems follow a service philosophy, where services are characterized by their functionality and quality-ofservice parameters. We develop a design hypothesis that takes the service characteristics into account in a stepwise fashion. We then validate the hypothesis for traditional database characteristics, demonstrate for novel requirements how these would affect architectures, and finally apply it to the current 4-tier server architectures.