No Pickups should happen before all deliveries are done at depot


Is there a way to prevent further pickups until the vehicle is fully unloaded at the depot.

In our case, the vehicle should start from the depot, do pickups up to its capacity from the different locations, come back to the depot and must unload the vehicle completely and again go for further pickups and repeat the cycle. But many times while doing deliveries to the depot, the vehicle goes for further pickups without unloading the whole capacity.

Is there a proper way to model this scenario. We have read many threads discussing hard activity constraints to solve this but still didn’t get the solution.