Unloading Tank and Optimally Schedule Ships to Load

Hi,

I have a problem where a tank is being loaded by continuous production and ships of fixed volumes are used to unload the tank, How can I develop an optimizer for this problem to ensure tanks don't overflow and ships are least delayed. I expect this to a simple MILP but I don't see any exaples for this online. I am sure its a common industry problem. Can someone please guide me with ideas and approach?

I have a plant producing at a rate of 100 tons/hr

Also, I have 4 ships,

Capacity Days

ship1 3600 2

ship2 2700 3

ship3 3100 4

ship4 2500 4

With capacity as 3600,2700,3100 and 2500 tons .

They take 2,3,4 and 4 days respectively to come back to pickup again.

How do I develop a optimized schedule for the same.

TIA!