I,m not familiar with that industry so I don,t know what it can load or unload. Go into surveyeyor, buildings tab, click the ? button and click on the dairy. This will open the dairy,s window and you can then see what it can load and unload. As I said I don,t know this industry but there should be a list of commoditys with probably load and unload beneath each one. There may only be milk" and an option to load but not unload. If so you cannot unload milk. However if there is aun load option you should set the amount to be consumed each minute, say 10000 and an initial amount ready for unloading (optional) when the session starts.