Service level is: the probability of stocking out. the probability of not stocking out and calculated as the cost of a shortage divided by (the co shortage + the cost of overage) for single-period models the probability of not stocking out. something that should be minimized in retail. calculated as the cost of a shortage divided by (the cost of shortage + the cost of overage) for single-period models. Which of the following statements regarding a pull system is TRUE? None of these is true of a pull system. Large lots are pulled from upstreitn stations. Manufacturing cycle time is increased. Problems become more obvious. Work is pulled to the downstream stations before it is actually needed