In Odoo's Manufacturing module, you can track labor or machine time by creating work orders and routing operations for each manufacturing order (MO). Each routing operation can have a duration that represents the amount of time required to complete that operation.

To add labor or machine time to an MO as it is completed, you can use the "Time Tracking" feature in the Work Orders app. Here are the steps to set up time tracking for your manufacturing orders:

1. Install the "Work Orders" app in Odoo. This app allows you to create and manage work orders for your manufacturing processes.

2. Open the manufacturing order that you want to add labor or machine time to.

3. Create a work order for the MO by clicking the "Create" button in the "Work Orders" section.

4. In the work order form, you can add routing operations that represent the different steps in your manufacturing process. For each routing operation, you can specify the duration in hours or minutes.

5. Once you have added all the routing operations, you can start tracking time by clicking the "Start" button next to the first operation.

6. As your workers complete each operation, they can log their time by clicking the "Log Time" button and entering the number of hours or minutes that they worked.

7. Once all the operations are complete, you can mark the work order as "Done" and the time tracking data will be automatically added to the MO.

Using the "Work Orders" app, you can track labor or machine time for each manufacturing order and get a better understanding of your production costs. There is no need to create a separate item for labor or machine time.