A number of problems may arise from architectural requirements modeling,
including alignment of it with business strategy, model integration and
handling the uncertain and vague information. The paper introduces a method
for modeling architectural requirements in a way of ontology-based and
capability-oriented requirements elicitation. The requirements can be modeled
within a three-layer framework. The Capability Meta-concept Framework is
provided at the top level. The domain experts can capture the domain
knowledge within the framework, forming the domain ontology at the second
level. The domain concepts can be used for extending the UML to produce a
domain-specific modeling language. A fuzzy UML is introduced to model the
vague and uncertain features of the capability requirements. An algorithm is
provided to transform the fuzzy UML models into the fuzzy Description Logics
ontology for model verification. A case study is given to demonstrate the
applicability of the method.