Abc Classification - What is the ABC classification of service level?

'A' goods are the top 20% of products categorized as 'Critical few' with a high service level of 96-98% according to the ABC rating of service level. The following 20-30% of products are considered 'Interclass' and have a medium service level of 91-95%; these are the 'B' items. Items with a lower service level of 85-90% are categorized as "C," and they make up the final 50-60% of all products.