A manufacturing monitoring assistance device includes: a model creation unit creating a computation model when a product as a sample is normal, based on a three-dimensional form acquired from the product; a simulation unit creating a corrective computation model when the product is abnormal, by adding a sample of an abnormal portion in the product to the created computation model, and performing a simulation on each of the computation model and the corrective computation model; and a monitoring method determination unit determining a method for monitoring a manufacturing process for the product, based on an abnormality index being a difference between an output from a sensor as a result of the simulation performed on the computation model and an output from a sensor as a result of the simulation performed on the corrective computation model, and causing an output device to display the determined method and the abnormality index.