In service-oriented architecture (SOA), workflows coordinate the services and artifacts to provide solution of certain business goals, and can be viewed as reusable assets in design level. A well-structured workflow may still fail or produce unanticipated run-time behavior because of abnormal artifact manipulation generated from twisted temporal and structural relationships between activities. The methodologies for eliminating such artifact anomalies caused by structural factors have been studied in several previous works; however, the temporal factors are still seldom addressed in related analyses. In this paper, TSworkflow, structured workflows with temporal consideration, are considered as reusable assets in SOA, and the issues of detecting artifact anomalies in TSworkflow are discussed. The artifact anomalies generated from the twisted temporal and structural relationships between artifact operations in TSworkflow are described. The obstacles in the detection such as loops and blank branches are discussed. Finally, we sketch an algorithm detecting artifact anomalies in TSworkflow to assure the correctness of the corresponding reusable assets in SOA.