It would depend on the probability than this situation occurs (experience say to us that is very low) and the impact that could result if they materialize.
Probability
In he worst scenario (from a BC point of view, of course): all employees of a company share the winning ticket of the Christmas Lottery, that is 400.000€ for each ticket. Assuming that each employee has only 1 ticket and that the reaction of every employee is to leave their work with this 400.000€ - at least during a year... - this represents a probability of 1 between 100.000 of loosing 90% of the workforce on 22th of December.This probability is really low (0,00001), but anything can happen.
Impact
Impact that can cause loosing of employees will depend on each organization. As I explained in my previous post Components that support business, each organization has a different dependence percentage on the five kind of resources that support business: Premises, People, Technology Infrastructure, Information and Suppliers. Companies with a low dependence on Human Resources can stop reading. For the other companies, continue....If we have a high impact because of lack of human resources, risk could begin to be taken into account and, so, it could make sense to identify situations that could mitigate the impact that could cause this situations. Here we have to analyze two concepts:
- Looses to the organization in case of lack of 90% of the staff. Some organization have done this analysis because of the A flu Pandemic two years ago and it would be growing in a exponential way.
- How much cost to replace personal. Here we have some different procedures to act in case of a disruption, depending on the position of the employee. Some of them will be very difficult to replace and specific procedures has to be done for them.
- In order to grantee that the organization will have budget enough to face the lack of personal, is advisable to have a corporate participation of the ticket with the number of participations that whose prize will cover the contingency procedures cost.
- To protect key people, organization should establish an agreement through which employees will grant they will be working after the lottery drawn, for example, shielding the contract.