A television revival is an attempt to revive a defunct series by producing new episodes created for broadcast. Network executives may decide to attempt to revive a television program when they feel that a market once again exists for it. Revival is one of several programming strategies television networks employ to capitalize further on successful programs; among the other methods are spin-offs, cast reunions, and television movies based on the original program. An example of a successful revival outside of the U.S. is the 2005 British science fiction series Doctor Who.