In the manufacturing module you can use a Gantt view to see all the MO and WOs you have setup. The MOs are divided up between work centers.
If a work center describes a single machine, it makes sense that the machine could only be used to produce one MO at a time. Other MOs should not be allowed to overlap.
But in openERP MOs can over lap. Is there a way to make MOs not overlap in a work center?