1. A non-transitory computer-readable medium storing computer executable instructions that when executed by a computer cause the computer to perform a method, the method comprising: upon detecting a request for a report, recursively identifying backchain programs along a chain of programs that are involved in producing the report until reaching source programs of the chain of programs, where a source program is a program without a predecessor program or with a predecessor program that does not support backchaining, where the backchain programs are accessible to the computer, and where the backchain programs support executing based on whether inputs of the backchain program have been updated since the backchain program was last run; and beginning with the source programs from the chain of programs, progressively running selective programs in the chain of programs, whose inputs have updated since the report was previously generated, until data from the report is verified as current.