The manager of a large supermarket wants to explore possible policies regarding the number of lanes that are necessary to provide a satisfactory services to the customers.
The number of customers, and the volume of their purchases varies quite markedly at different times of day and the number of check lines should be adjusted to match that demand. Customers can move to other supermarkets if they have to wait for a long time in queue.
Rules for running super market: The manager is proposing some rules for when to open or close checkouts and the frequency for scheduling such decisions. But before trying this rules manager wishes to try them out in simulation.
Program to simulate working for different sets of parameters: The program that is to be developed for the manager is to start by accepting a set of inputs that define a particular set of control parameters for the manager’s rules. It is then to simulate one day of operation of the supermarket subject to these rules.
The simulation will involve some randomized customer traffic. During the simulation, various statistics will be gathered that characterize the distribution of the queuing times for the customers and the total amount of open-time and idle time for the checkouts.
At the end of a simulation run, these data are to be displayed. The manager may then wish to initiate another “randomized” run or may wish to repeat the run using the same “randomized” pattern for the customer traffic but with a changed set of parameters for the rules.
Time period simulated: Supermarket serves its customers when its opened. Super market keeps on serving its customers until the manager closes the doors. All customers are allowed to complete their shopping and must queue to pay for their purchases before leaving.
During closing period the manager checks the state of the shop regularly and closes any checkouts that have become idle. The super market finally closes when all the customers are served.
Customer traffic: The rate of arrival of customer is far from uniform and cannot be simulated by random drawing from a uniform distribution. Instead it must be “scripted”. The pattern of arrivals averaged for a number of days serves basic for this script.
Scheduling changes to checkouts: The manager is proposing a scheme whereby checks are made at regular intervals. This interval is one of the parameters for a simulation run.
When running a check on the state of the super market, the manager need to close idle checkouts, or to open checkouts to meet the minimum requirements for fast and standard checkouts, or to open extra checkouts to avoid excessively long queues at checkouts.