ABC analysis is a technique of inventory control in which the basic criteria is cost of the items. It is stated that a small number of items consume a big chunk of resources and vice versa. Around 10% of the drugs/store materials would cost 70% of the resources (called Group A), 20% of the drugs/store materials generally consume 20% of the resources (called Group B) and remaining 70% of the drugs/store material/items would consume just 10% of the resources (called Group C). It should be differentiated with VED analysis. Source: A Dictionary of Public Health 2013 3rd Edition.