Findings – The concepts of MCS (common sense) and MUS (uncommon sense) are established, as
well as O and M errors. It is suggested that within a mechanistic approach MCS is most appropriate in
conditions of high task certainty. Within an organic approach MUS is most appropriate in conditions
of low task certainty. An O error occurs when a mechanistic approach is taken, using common sense,
under low task certainty. Lack of appropriate resources deems such an approach unsuitable. An M
error occurs when a more risky organic approach (MUS) is taken when resources exist to make a
common sense decision.