With advanced multi-functional work center machine in production companies, you get more and more the following scenario to cover the work center planning. Example: Work center runs in 3 shifts. Shift 1 and 2 are under control by production people. 3 shift in the night is a ghost shift. This means the work center runs automatic without supervising by production people. Production worker is preparing (setup) the work center with Tools, prgramming code etc. for several planned productions orders. After setup is done, the work center is processing automatically the production orders in the planned shifts (in this case 3 shifts are planned). The following scenarios mus be considered: - Setup for the work center takes longer then one shift. - Planned and prepared production orders could take longer then the 3 shifts of the day. - Work center can produce the parts not only in sequnce of the production order, means production oder 1 gets produced first and then prodction order 2 etc., they even can do this in mix mode like part 1 of production order 1 gets produced and then follows part 2 or prodcution order 2 etc.. Both have an impact of planning the next Operation.