The Layouts tab related to a schematic diagram template lists all the schematic layout algorithms provided with Schematics and allows you to specify which schematic layout algorithms you want to be available or not for the schematic diagrams and to configure their default properties.
To edit the Layouts tab related to a schematic diagram template, select the schematic diagram template entry in the Schematic Dataset Editor tree and click the Layouts tab. By default, the Layouts tab content displays as follows:
The Layouts tab lists all schematic layout algorithms registered on your machine; a specific item is associated with each schematic layout algorithm and allows you to set the layout algorithm property values you want to be set by default for all the diagrams implemented by the related diagram template.
Specifying the availability of each schematic layout algorithm
For any schematic layout algorithm item in the Layouts tab, the Visible parameter allows you to specify whether the algorithm will be available or not for the diagrams based on the diagram template. When the Visible parameter value is unchecked for an algorithm item, this algorithm will not be available from the Layout Task drop-down list in ArcMap when any diagram based on the diagram template is active. By default, the Visible parameter value is checked for all algorithms.
Specifying the editability of schematic layout algorithm parameters
For any schematic layout algorithm item in the Layouts tab, the Editable parameter allows you the option to authorize the editing of the algorithm property values for schematic diagrams based on this diagram template. If the Editable parameter value is unchecked, the Layout Algorithm Properties button 
will be disabled in ArcMap for any active diagram based on the diagram template to prevent users from changing the algorithm property values for these diagrams. When the Editable parameter value is checked (default value), users can click the Layout Algorithm Properties button and edit the algorithm parameter values for the active diagram
Specifying each schematic layout algorithm's default parameters
For any schematic layout algorithm item selected in the Layouts tab, the Layout Properties button 
on the Layouts tab toolbar allows you to edit the algorithm properties page and specify particular property values. The specified property values will be the default values for the schematic diagrams based on the diagram template. If the Editable parameter value is checked, users will be able to change them, but when clicking Restore Defaults on the Layout Properties dialog box, the specified values will be those restored.
Learn about geo-schematic layout algorithms and their properties
Learn about hierarchical schematic layout algorithms and their properties
Learn about pure schematic layout algorithms and their properties
Specifying the schematic layout algorithms order
By default, the Layouts tab list displays in alphabetical order. The order in which the schematic layout algorithms display in this list is used to fill the Layout Task drop-down list in ArcMap when a diagram based on this diagram template is active. To change this order, select the item corresponding to the algorithm you want to move at another location and click either the 
Move Down or 
Move Up button on the Layouts tab toolbar to move the selected algorithm down one level or up one level.