BU275 Lecture Notes - Lecture 7: Pennsylvania Railroad Class Gg1
Document Summary
*there will be a participation exercise in class on monday, feb. 1. Arrival process: is the rate of arrival. Waiting room: can be finite or infinite, scheduling policy matters. Server s leave ex. is it first-come-first-serve? or depends on importance (ex. emergency room) *are interested in the amount of time customers spend in the system, how long is the line expected to be on average. Time on average that a server is being used time/servers. 1/ expected value of arrivals, average. Burlingham mills: notation g/g/1 customers the fabric servers dyeing facility, s = 1. 1/ = (1*. 2)+(2*. 4)+(3*. 3)+(4*. 1) = 2. 3 = 1/ 2. 3 = . 43. 1/m = (. 5*. 2)+(1*. 5)+(2*. 3) = 1. 2 m = 1/ 1. 2 = . 83. Utilization of servers = /(s*m) = . 43/(. 83*1) = . 52 since . 52 < 1, this is a sustainable queue. Production problem: customers = jobs, = 4, servers = lathes. U = = . 5, l = 2.
