1. General rule: All employees and family, friends, acquaintances, etc. of crew are first accomodated into business class irrespective of overbooking state of economy.

2. If economy is overbooked but KL is not sure if everyone will show up, no one is op-upped until the last passengers start straggling in: usually backpackers running late on cheap tickets. They are handed a business class ticket as they board. Unless of course, there are still employees who have not been upgraded in which case the backpacker may be offered a denied boarding compensation.

3. If economy is overbooked and KL knows that economy will be overflowed, then they look at the waitlist for employees & friends and reserve enough business seats for them. If there is anything left over then upgrades are processed based on Flying Blue elite level, sometimes also looking at ticket fare class. If economy is still running over and there are still seats left in business other Skyteam elites will be upgraded.

There is a new program being tested which will allow Flying Blue members to upgrade for a fee out of Schiphol and some stations (including JBO?)
Don't know if NW WP can participate.