Abnormality determination method and production management system

An abnormality determination method is provided in a production management system that manages a production line including a first production device, a second production device, and a third production device. At least first operation condition data and third operation condition data among first operation condition data in a first production device, second operation condition data in a second production device, and third operation condition data in a third production device are acquired (S11), and when it is determined that the second operation condition data is not acquired (S13 "No"), the first operation condition data and the second operation condition data are acquired (S13 "No"). A virtual operation time is predicted on the basis of the operation time of the preceding and succeeding processes, a virtual waiting time is predicted on the basis of the waiting time of the preceding and succeeding processes, and virtual operation condition data corresponding to the second operation condition data including the