1) A warehouse holds 1000 cubic meters of cartons. These cartons come in three sizes: little (1 cubic meter), medium,(2 cubic meters), and large(3 cubic meters). The cartons arrive at the following rates: little, every 10+10 minutes; medium, every 15 minutes; and large, every 8+8 minutes. If no cartons are removed, how long will it take to fill an empty warehouse? (requires use of Visual Logic)
2) A milling machine department has 10 machines. The runtime until failure occurs on a machine is exponentially distributed with a mean of 20 hours. Repair times are uniformly distributed between 3 and 7 hours. Use a simulation run length of 2000 hours and answer the following questions-
How many repair persons are required to ensure that the mean number of machines running is greater than six?
If there are two repair persons, estimate the expected number of machines that are either running or served.
(requires use of resources)
3) Consider a manufacturing system comprising two different machines and a single operator who is shared between the two machines. Parts arrive with an exponentially distributed interarrival time with a mean of 3 minutes. The arriving parts are one of two types. Sixty percent of the arriving parts are Type 1 and are processed on machine 1. These parts require the operator for a one-minute setup. The remaining 40 percent are part Type 2 and are processed on machine 2. These parts require the operator for a 1.5-minutes setup operation. The service times (excluding the setup time) are normally distributed with a mean of 4.5 minutes and a standard deviation of 1 minute for Type 1 part and a mean of 7.5 minutes and 1 standard deviation of 1.5 minutes for Type 2 part.
Two different priority schemes have been proposed for allocating the operator between the two types of waiting jobs. The first scheme is to assign priority to the Type 1 jobs. Under this proposal, a job Type 2 setup will only be performed if there are no job Type 1 setups waiting to be performed. The second proposed is to alternate the priority between the two types.
Simulate each of these systems for an 80-hour period; and collect statistics on the machine and operator utilization, the average number of parts waiting for each machine, and the average flowtime for all parts.
(requires use of resources, and resource priorities)
4) In the preceding problem, the operator periodically must do paperwork associated with the parts flowing through the work area. the time required to perform this paperwork has a triangular distribution with minimum, mode, and maximum values of 3, 5, and 8 minutes, respectively. The time between paperwork requests is exponentially distributed with a mean of 25 minutes. The paperwork is prioritized over serving parts. In addition to the previous statistics, collect statistics on the utilization of the operator for performing the paperwork.