Copy a previous instance of a workflow into a new request.

What do you mean by "workflow"?

A process by Appian terms. We want to take the original input from one (process) instance, create a copy into a new "request" and allow a "clone" or new request that leverages information from a previous "request"

I've used process "templates" to mimic this behavior. The data is stored in the database and loaded into a SAIL form in a paging grid and data from the selected item's data is loaded into the process. Templates are managed via an Action.

I agree with Nathan, this is the way even I have used it.

Thank you for your reply! When you say "stored in the database" are you referring to an external data source or the internal Appian db. Do you increase the archive time for tasks, assuming it is in the internal db?

I would recommend using your relational database to store this data. You shouldn't change your archive interval to support this functionality.

I'm not sure can you extract the data from arbitrary process without your own plugin.

The simplest way is to save the template data into a separate CDT and use it when start a new process of particular type. If you need to keep all inputs the process should save its input into this CDT for future use. But you'll need a separate CDT per process model set of input data.