This paper is about a generic method for designing shared memory BIST systems. In order to be of practical use, such a method should work with whatever memory kinds and BIST components are available for the technology used. It should accept arbitrary sharing rules for grouping memories under a wrapper, and it should take individual values of BIST component area, memory test time and memory testing peak power as parameters. We present such a method that uses genetic algorithms for its optimization phase, together with its industrial implementation, and numerical evidence for the value of the method. It is integrated into STMicroelectronics' BIST definition flow.