A process plan creation device configured or programmed to create a process plan of pipeline construction includes a data storage to store basic data for use in creating the process plan, an information acquirer configured or programmed to acquire information concerning a work progress pattern in the pipeline construction and construction information necessary to create the process plan, a work time calculator configured or programmed to calculate a work time in accordance with the work progress pattern using the basic data stored in the data storage and the information acquired by the information acquirer, and a process plan creator configured or programmed to create the process plan based on the work time calculated by the work time calculator.