Main menu:

A common calculation is:

A items= items representing the top 80% of total dollars

B items= items representing the next 15% of dollars

C items= items representing the bottom 5% of dollars

A items = 4 times per year

B items = 2 times per year

C items = 1 time per year

A items = plus or minus 1% quantity variance from perpetual balance

B items = plus or minus 3% quantity variance from perpetual balance

C items = plus or minus 5% quantity variance from perpetual balance