Chains are good way to automate repetitive tasks, such as plotting, applying mapfiles, etc.

To create a new chain, go to Utilities => Chains => Create

On the Create/Edit Chain panel, enter a Chain File name and then use the Insert button to add a new command.

Select the command Type by using the browse button on the right.

For more information, refer 12d Reference Manual s.28.4.1 Create/Edit a Chain
For all of the available Chain Commands, refer s. Chain Commands