Hello everyone!
Our job this week was to formulate the costs function for the system. It is important for HAMBURGER’s manager to be able to measure the costs of the system because one of its jobs is to maximize the revenues given by the system operation. For this task, we include the following variables:
- The expected number of entities in queue for the first station: WIPq. The costs function doesn’t include the expected number of entities in queue for the Cooking & Delivering and the Sauce stations because once the client pays, HAMBURGER doesn’t assume costs for queues in other stations.
- The proportion of time that servers are idle. The costs function includes the cost of paying a server who is not working per minute.
- We assume that a client who decides to enter into the system is willing to wait as long as it takes.
- The cost associated to losing a client is the expected value of the purchase. This cost is particularly important because it represents a missed sale for HAMBURGER.
- The cost associated to an unoccupied server is the wage per minute paid to an employee.
- For a client to leave the restaurant, it is necessary that the WIPq for the Ordering station is 15 or greater.
The costs function is define as follows:
