财务管理与财务分析运营管理课件c(编辑修改稿)

财务管理与财务分析运营管理课件c(编辑修改稿)内容摘要：

ve… Mean = T Variance = T 169。 2020 Pearson Education  The exponential distribution describes the probability that the service time will be no more than T time periods. Probability Distributions Service time If the customer service rate is three per hour, what is the probability that a customer requires less than 10 minutes of service? P(t ≤T) = 1 – eT μ = average number of customers pleting service per period t = service time of the customer T = target service time P(t ≤ hr) = 1 – e3() = 1 – = Example Mean = 1/ Variance = (1/ )2 169。 2020 Pearson Education Operating Characteristics  Line Length: Number of customers in line.  Number of Customers in System: Includes customers in line and being serviced.  Waiting Time in Line: Waiting for service to begin.  Total Time in System: Elapsed time between entering the line and exiting the system.  Service Facility Utilization: Reflects the percentage of time servers are busy. 169。 2020 Pearson Education SingleServer Model  The simplest waiting line model involves a single server and a single line of customers.  Assumptions:  The customer population is infinite and patient.  The customers arrive according to a Poisson distribution, with a mean arrival rate of    The service distribution is exponential with a mean service rate of   The mean service rate exceeds the mean arrival rate.  Customers are served on a firste, firstserved basis.  The length of the waiting line is unlimited. 169。 2020 Pearson Education  = Average utilization of the system =   L = Average number of customers in the service system =   –  Lq = Average number of customers in the waiting line = L W = Average time spent in the system, including service = 1  –  Wq = Average waiting time in line = W Rn = Probability that n customers are in the system = (1 – )n SingleServer Model 169。 2020 Pearson Education SingleChannel, SinglePhase System Arrival rate ( = 30/hour, Service rate ( = 35/hour Average time in line = Wq = () = hour, or minutes Average time in system = W = = hour, or 12 minutes 1 35 – 30 Average number in line = Lq = (6) = customers Average number in system。