PURPOSE: To easily generate a Gantt chart having optional constitution contents and to freely customize it.

CONSTITUTION: This system is equipped with an object storage part 12 storing plural objects for displaying respective constituent elements of the Gantt chart for displaying and altering scheduling data of the scheduling data on the basis of set slot values, a Gantt chart generation part 13 which generates the Gantt chart corresponding to the setting contents of the slot values by reading the objects having the slot values out of the object storage part 12, a Gantt chart display control part 14 which displays the generated Gantt chart on a display device 16, and a Gantt chart editing process part 15 which alters the constitution contents of the Gantt chart by varying the slot values of the objects.