Steps:

1.Right-click on a use instruction bar on the resource Gantt chart. The use instruction bar popup menu will be displayed.
2.Select [Operation] – [Edit Operation…] from the use instruction bar popup menu. Properties of the use instruction for the operation you selected will be displayed in the properties window.
3.Select the General tab from the properties window.
4.Specify a time for the property “User specified production time”.
5.The specified production time will be considered as a time constraint during scheduling.
6.You can specify the user specified production time for an operation only after Asprova generated the operation from scheduling.