How do I ensure that the default sizes of visual model objects cannot be changed?

The default dimensions of the process step objects in the visual model are defined as 100 in width and 100 in height. It is possible to change these dimensions, and you can change the width and height of the process step you want to change from the System>``````>Process management>``````>Process step type menu path by pressing the edit icon next to it and then clicking the "Dimensions" button in the window that opens.