A computer-implemented method comprising: determining types of items that are required to perform a particular type of surgery； generating data for a graphical user interface that when rendered on a display device, displays: a surgical tray visualization of a surgical tray, with the surgical tray visualization comprising: one or more required material visualizations of the one or more types of items that are required to perform a particular type of surgery, with a required material visualization specifying how many of a particular type of material or instrument is required for the surgery and further specifying how many of the particular type of material or instrument has been virtually played on the surgical tray； for a type of item required, item placement information, selection of which causes the surgical tray representation to be updated to account for the selected item and to virtually place the selected item on the surgical tray.
