To conclude a work order all the work tasks connected to the work order should be finished. Which means work planned on the work tasks must be performed reported and invoiced to the customer.
When you have filled in all necessary information and have completed the work, change the status to 'Finished' to conclude the work order. As result, the work order becomes historical, and could be used for information purposes only. The information on a historical work order can only be changed, or reused when you are using the Reopen right mouse button option.
The reopen feature has the following aim; if you for example have forgotten to register any work done, it is always possible to add this on to a historical work order.