According to Tattoos and Body Piercings at About.com, an industrial piercing heals in four to six weeks. If problems occur during the healing process, one should allow two to four more weeks before changing the earring. The healing time relies on the alignment, balance and aftercare of the initial piercing.
Wikipedia states that most industrial piercings take from three months up to a year to heal. During the first month of cleaning, one should clean it four times a day with a cotton swab dipped in warm, unionized salt water, unscented antibacterial soap or the provided cleaning solution. Wikipedia recommends using the cleaning solution for best results. One should only change the piercing earring or jewelry after the initial piercing is healed completely.