CBS » by Andy Dehnart / January 11, 2012, 11:46 AM More reality TV is being developed by CBS, which has primarily relied upon its standby trio of Survivor, Big Brother, and The Amazing Race for the past 12 years. With the exception of Undercover Boss , which started strong but fizzled fast, especially in terms of buzz, CBS hasn’t launched a successful reality show in years. “We’re in the fortunate position of having successful, long running franchise shows,” CBS Entertainment President Nina Tassler told TV critics this morning. “That is the reality of reality. Those shows Survivor and Race and Big Brother had ratings growth, [and] they continued to.” Tassler said that “this year going forward in summer, we’re being very aggressive. We have a number of shows in development in the unscripted space that we have early triggers on so we can get them ready and we can have them on the air in fall. We do incredibly well with Big Brother. They had ratings growth last season.” She didn’t g...