The unproductive-layer is important when:
You have employees with a fixed contract;
Work with surplus and shortfall hours;
Keep track of holidays.
In order to calculate the amount of surplus and shortfall hours, L1NDA looks at the amount of contract hours of an employee and the amount of scheduled hours.
EXAMPLE - Fixed hour contract
Bianca has a 38-hour contract, but is absent for 3 days due to either a 'waiting-day', illness, holidays, special leave, unpaid leave or a public holiday [ADD LINKS HERE!]
All these type of absent days need to be registered in the unproductive-layer in order for L1NDA to correctly calculate the hours. Bianca will not make any shortfall hours in this example, as you've registered her in the unproductive layer.
The unproductive layer is not used for employees with an hourly contract. By adding their (un)availability, they can communicate whether they want a day off or go on holiday but this layer does not have an effect on any balance.