A device system includes a terminal device and an information processing device. The terminal device includes a detector and a first notifier. The detector detects at least one of data representing an operation performed by a worker with respect to the terminal device, data representing an environmental value of a plant, and data representing biological information of the worker. The first notifier notifies, to the information processing device, first historical data representing a history of data currently detected by the detector. The information processing device includes a storage and a proposer. The storage stores second historical data representing a history of data detected by the detector in the past. The proposer proposes an operation which should be performed with respect to the terminal device by using the first historical data notified by the first notifier and the second historical data stored in the storage.
