The shopping project – contingency time

Do you go on weekly or fortnightly supermarket shopping expeditions?  Either way, this blog item might help you determine your shopping contingency time (or contingency time for any other project) – that’s the extra time needed to allow for possible delay-causing incidents during project implementation.  This blog item shows us how to determine contingency time somewhat more scientifically than merely thinking of a number and doubling it or throwing dice.

Part of the solution is to apply what’s called the PERT formula (Program Evaluation and Review Technique).  This formula allows us to determine a project’s best estimated time (BET) or duration – depending always on the accuracy of our input data.  (PERT is a weighted-average estimate, heavily weighted towards the most likely duration (ie, 68.3%), which is one standard deviation (sd) either side of the norm – for … Read More »


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