When the Business Times publishes our Fast 50 List later this year, it will be the 24th time we have identified and honored rapidly growing private companies in the region. Originally a List of 100 fast-growing private companies, the inaugural group in 1997 was known as the Pittsburgh 100. Three years ago, the List was cut in half, increasing the exclusivity for those making the ranking, and renamed the Fast 50. But one thing that has not changed over this period is the qualification requirement.…