Configure the pre workflow parameter if you want to run a specific workflow before you run the workflow from the current plan. Configure the post workflow parameter if you want to run a specific workflow after you run the workflow from the current plan. You can select an existing workflow in the PowerCenter folder that is associated with the project.
The pre workflow step is the first step in the process. The actual TDM workflow starts after the pre workflow completes successfully. The post workflow starts after all the TDM workflows complete successfully.
For example, you want to move files from the production area to the test area before you mask them. After you mask the data, you want to run statistics to optimize the tables. First, the pre workflow copies files from one location to another. Then TDM workflow masks the data. After TDM loads the masked data into the target, the post workflow runs the statistics.
You can disable triggers in a pre workflow and then enable them in a post workflow.