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A production system requires four machines with the following productivity and layout: A B O 15 18 20 A B C D What is the overall productivity of this system? 25 C D 20 units/hr 18 units/hr 15 units/hr 25 units/hr A service level is an implicit or explicit agreement between the service provider and consumer that defines an acceptable level of service the level of service that can be provided within a given span of time an agreement between the service provider and consumer as to the extent of overtime that will be assigned to a particular job an agreement between the service provid and consumer as to the number of employees who will be assigned to a particular job The difference in time between planned order release and planned order receipt ensures safety lead time O depends on lead time required O depends on inventory holding cost O is called time phasing