APPS 9 MWO Amount to Collect

May be you can try below:

1) Add a custom field to active_work_order_tab -> ActiveSeperate Lu

2) In the server side, when the work order state change to completed, you can call a method to update the custom field.

3) Then amount value in the custom field will push down to device.

4) You can add custom field to mobile screen via UI designer.

The problem is that the state of the work order doesn’t change until the technician either returns or keeps the work order on MWO. The state would then be changed after the technician needed the dollar amount returned to them.

Isn’t it enough to get amount value after complete the work order. i.e. complete and keep ? If the amount can be calculated and trigger before compete the work order you can try any earlier state change or any update in reporting screen.

You could add a boolean custom field (tick box) on a relevant screen e.g. report in screen for example that would trigger the calculation in the back end and update a second field as Bandula suggests, or maybe use a survey that triggers before complete that has a simple Yes/No question asking if the tech thinks the WO is ready for return amount calculation.

In either of these scenarios you'd have to be online though.

In Apps 10 you'd have some more options as you can  now execute custom actions through a button for example.