Requirements Trade-offs During UML Design

In English Designs almost always require trade-offs between competing
design choices to meet pervasive system dependability
requirements (e.g., security, performance and fault tolerance
system goals). In some cases, dependability requirements
are realized by functionality that cross-cuts designs.
Aspect-Oriented Modeling (AOM) methods allow developers
to localize such cross-cutting functionality in design
modeling views called aspects. Aspects can be composed
with other design views to obtain an integrated view of a design.
This paper presents a technique that extends such
methods to cover dependability requirements that are not
directly realized by functional structures in a design. Performance
goals provide examples of such requirements. We
also present a trade-off mechanism to rank feasible solutions
with respect to requirements priorities between different
dependability requirements. The paper applies this
technique to an example that has performance, fault-tolerance,
and security requirements.