Architectural design decisions are commonly agreed as one of the main elements that constitute architectural knowledge. To avoid knowledge vaporization, architectural decisions and their rationale need to be documented in a systematic manner. Various works have been done on representing architectural knowledge. Process decisions are one type of design decisions that existing models have paid little attention to. In this paper, we specifically address process decisions in the SOA domain. In doing so, we challenge architectural knowledge representations by mapping two SOA process decisions against a core model of architectural knowledge. The result suggests that existing models need to be extended in order to model SOA process decisions. Categories and Subject Descriptors D.2.11 [Software Engineering]: Software Architectures General Terms Design Keywords Architectural knowledge, model, process decisions, serviceoriented architectures.