Three scenarios which I guess would be handled with a series of if statements.

1: New part is received from the distributor.

2. part is removed by a technician for use on a service call.

3. part is returned from tech to warehouse

   a. defective part which was replaced is returned to the distributor

.  b. part is returned unused and will be added back into our inventory on hand

a separate form is used to document the activity.  Technician or warehouse manager enters the part and the quantity and the type of activity (1,2, or 3 above)

There is a lookup field in the activity form that relates the activity to the inventory on the part number.

Now, I have to update the quantity on hand based on the activity.

Since I don't want the activity to update the inventory more than once, I assume that the update will be "on Add/On Success" (is there a way to prevent editing of a record once it's saved)

So now the issue is how to get back to the inventory and update the correct record.  I think I understand the fetch record process but I haven't found the deluge script to update the form.