Sometimes, two or more films in a series are shot and produced "back-to-back", which means simultaneously or within a short space of time. This is usually done to eliminate the need to rebuild sets and re-hire actors for sequels, and maintain audience interest in the film series. Films produced this way usually have a well-planned pipeline, where the first film may be in post-production as the second is being shot. The following is a list of films that have been produced this way: