Intelligent maintenance cost standard, do not directly say % a few, give me an industry on the documents available, recognized standards, thank you!

Generally there are charged in accordance with the proportion and in accordance with the cost estimation method, generally speaking (1) Proportion method: in accordance with the contract 10-15% of the amount of fees charged for maintenance, including weekly inspections and monthly inspections and specific failures in a timely manner maintenance. Another equipment damage, according to the price of the two sides agreed to replace or repair. General will provide a list of quotations for wearing parts covered in the maintenance contract. (2) cost estimation method: labor costs + material costs + overhead + profit. The way to take the fee with the size of the district has a relationship.