in a iron mine are 3 identical digging machines called shovels operating at the same time. They load boulders with iron ore into trucks. The trucks drive to a place where 3 identical machines called crushers crack the iron from the boulders. Here the trucks are unloaded to the shovels for a new load. Each shovel or crusher can serve one truck at the time.
* the loading of one truck could take anywhere between 3 and 7 minutes.
* It takes 5 minutes to unload one truck (lognormally distributed with a standard deviation of 2 minutes.
* All trucks are identical and have a capacity of 30 tonnes. This is also the exact load for a truck loaded with ore.
* the time for a truck to drive from the shovels to the crushers is uniformly distributed between 20 and 40 minutes. The time to drive back with an empty truck is uniformly distributed between 15 and 25 minutes.
* Before you start building the model in ED, first think of how to model the process as simply as possible by disregarding unimportant aspeccts.
* determine the minimun number of trucks needed to meet an averge production of 1000 tonnes/hour. Run the model 10 times for 400 houes with a wromup period of 40 hours.
* what happens if you substantially increase the number of trucks? Calculate the averge output of a truck in different scenarios!