ITGS Class Work - Models and Simulations

ITGS SL1/HL2
Modeling/Simulations Practice

1. When customers visit a supermarket, they do not expect to wait in checkout queues for too long, however the supermarket manager cannot afford to have all the checkouts open all of the time. In an attempt to solve the problem the supermarket manager may decide to make a computer model using a spreadsheet to calculate the optimum number of checkouts that should be open at any time. N07P1

(a) Define the term computer model. (2)
Computer model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system. Computer simulations vary from computer programs that run a few minutes, to network-based groups of computers running for hours, to ongoing simulations that run for days. A computer model would and could be used here at this supermarket in order to help management decide how many cashiers to have open throughout the day because they would be able to predict how many cashiers would be necessary to make checkout queues as short as possible.

(b) Describe two inputs into the model that would be needed in order to calculate the best number of checkout operators. (4)
Two inputs into the model that would be needed in order to calculate the best number of checkout operators could be the busiest times of the day in which grocery sales are very high (i.e. morning, afternoon, nighttime) and on what particular days that sales may be higher than others (i.e. weekend sales compared to weekday sales). With these two inputs, management can see at what times of the day grocery sales are high which can help them to decide how many cashiers to have open at the time. For example, if grocery sales are higher in the afternoon than they are in the morning then management can have more checkout lines open then and less in the morning. Also, with computing what days are the busiest, management can see what days they need to have more cashiers open all the time rather than one particular time period. For example, if the weekend is busier than the weekday, in regards to sales, then more checkout lines would have to be open on Saturday and Sunday because that is what the computer model has calculated and predicted.

(c) Explain why this or any other computer model may not give accurate results. (4)
However, even with the input of very distinct information, a computer model can never be a hundred percent accurate in reality. This is due to the fact that with information being entered into the computer model system, other information that deals with that certain specific area is sometimes added or left out, leaving the possibility of inaccuracy very high. For example, if the management had the input of specific times during the day when grocery sales where high compared to times when they were low, consistently changes from day to day, month to month, year to year, and so one. So with the input of specific times and days when grocery sales are higher than normal, the probability that something in that given data is going to change or has already changed is nearly 100%. To say that everything in the world maintains consistency we’d be telling lies. Everything in the world is changing – even the little things such as days with higher grocery sales profit – and this is why no matter what computer model someone uses to find out something, it can never be completely accurate.



2. Computer models and computer simulations are often used by businesses to test and train staff. One situation where a computer simulation is used is in the training of airline pilots. M07P1

(a) Define the term computer simulation. (2)
- It is based on a mathematical model
- It is computer software
- The technique of trying to represent the real world in an artificial fashion

(b) Describe two input devices that would be used in a pilot training computer simulation. (4)
A joystick and a microphone would be used in a pilot training computer simulation. This is because the joystick would allow the pilot to maneuver the plane and allow him/herself to make the plane go where it needed to go and avoid obstacles, etc. A microphone would allow the pilot to talk to base control and receive information that would be help the pilot with where the plane was going or if there was a problem, he can report it and explain where he is or what is going on.

(c) Explain one benefit and one problem associated with training pilots on simulators instead of using real planes. (4)
One benefit associated with training pilots on simulators instead of using real planes is that the plane is not actually flying which reduces both the fuel cost and the risk of injury. If the simulation is used, less money has to be spent on aviation fuel and also the pilot won’t be in any physical danger. A problem associated with training pilots on simulators instead of using real planes is that if the model is incomplete or inaccurate, the simulation will not create a perfectly crafted artificial representation of flying conditions. If the simulation is wrong then the information distributed by the model is also wrong. Also, with using a simulation, not every type of physical weather condition or other conditions can be taken account for, so therefore one can say that a simulation is not the best thing to use due to the chance that the pilot is not receiving proper training and should be put out in an actual plane instead.