1. A data processing method comprising: causing displaying a first user interface at a first computer; receiving at a production manager computer, from the first computer via the first user interface, scene metadata defining a plurality of scenes of a media production; causing displaying a second user interface at a second computer that is different from the first computer; receiving at the production manager computer, via the second user interface, at a time after the scene metadata was received and before closing the media production, item metadata for a particular item appearing in the media production, wherein the item metadata specifies a scene, from among the plurality of scenes, in which the particular item appears; using the production manager computer: based on the scene metadata and the item metadata, creating a record in an item database that associates the particular item with the specified scene; determining one or more time values representing a time period during which the particular item appears in the media production based on the scene metadata; generating data specifying when the particular item and each of a plurality of other items appears in the media production based on the time period, wherein the data includes the one or more time values; wherein the method is performed by one or more computing devices.