ABSTRACT

Trucks in a mine arrive at a single repair bay where they need to have a part overhauled. They arrive in a Poisson stream every 5.25 hours. One worker takes the damaged part out, whereas a second prepares the replacement part. This preparation takes place simultaneously with the removal. Removal of the damaged part takes a time given by the normal distribution with a mean of 3.75 hours and a standard deviation. of .45 hours. Preparation of the new part takes a time given by the normal distribution with a mean of 4 hours and a standard deviation of .4 hours. Once both of the jobs are done, the first worker readies the truck for the new part whereas the other worker does minor adjustments to the part. The first worker takes .25 ± .15 hours whereas the second worker takes .2 ± .1 hours to do the adjustments. Once both of these jobs are done, the truck can leave the service bay. When a truck arrives at the service bay, work cannot begin until both workers are free.