You can layout the lanes vertically or horizontally.
You can change the layout of a process at any given time. This change applies only to that process.
For more information on how to change a process lane layout, see Changing the Process Lane Layout.
You can define which layout to use when creating a new process in a project. Note that the layout preference is defined by project and does not affect processes that already exist.
For more information on how to change the lane layout for the new processes in a project, see Defining the Lane Layout for the New Processes in a Project.
You can define the layout to use when creating a new project. The new projects you create use this preference to define their layout. For example if you prefer the horizontal layout, you might want to set this preference so that all the projects you create use horizontal layout for the new processes.
For more information on how to define the lane layout for new projects, see Defining the Layout for New Projects.