On the one hand this study presents an ISM modelling of 1o well accepted manufacturing flexibility dimensions. On the other hand it introduces two manufacturing cell formation heuristics in a simple and lucid manner. The heuristics have the ability to consider manufacturing flexibility and production related parameters in a simple manner. Both the heuristics are based on commonality score based clustering algorithm, however Heuristic-II has the ability to go with any other clustering procedure. It would be useful in realistic manufacturing cell formation for low to mid-size FMS.