edit my questionBackground

The ICT building has $F=7$ floors and normally has $N=3$ functional elevators. People arrive to the building at random times and enter on the ground floor $($Floor $1)$ according to a

Poisson arrival process with an average aggregate arrival rate of lambda $($e$.$g$.,$ lambda $=0\mathrm{.}5$ people per minute$).$ They request an elevator, enter it$,$ ride upwards, and get off at a floor

that is chosen uniformly at random from the remaining $(F-1)$ floors. They stay at work on that chosen floor for a randomly chosen amount of time $($Exponential distribution, with mean

$60\mathrm{.}0$ minutes$),$ before returning to the elevators, requesting one, riding down to Floor $1,$ and departing from the building. The performance metric of interest is the user$-$perceived

response time, which is the elapsed time between requesting an elevator and getting off at the desired floor $($i$.$e$.,$ once on the way up$,$ and once on the way down$).$

There are many possible variations that can be made to the configuration and operation of elevators: number, speed, capacity, scheduling. Your goal is to explore a small subset of these

possibilities, and understand the impact on user$-$perceived response time.

The "performance" of an elevator depends greatly on its scheduling algorithm. In particular, there are several choices for what an elevator can do when multiple user requests are

pending. One choice is to serve requests strictly in timestamp order, called First$-$Come$-$First$-$Serve $($FCFS$).$ Another is to service the "closest" request, regardless of the direction being

traveled. This is called Shortest$-$Seek$-$Time$-$First $($SSTF$).$ Another choice is to only service requests that are in the same vertical direction as is currently being traveled. This is called

Linear Scan. The choice among these policies is especially important when load is high.

Another factor affecting elevator performance is its idling policy. That is$,$ there are several choices for what an elevator should do when it is empty: stay where it is$,$ go to the bottom floor,

go to the top floor, or go to the "middle" floor. This policy is especially important at light$($er$)$ loads, but is less important at higher loads, when the elevator rarely empties.

Your initial simulation experiments will have just a single elevator $(N=1).$ In terms of other parameter settings, you can assume that $F=7,$ and that the movement time between

adjacent floors of the building is always exactly $10\mathrm{.}0$ seconds, regardless of occupancy, distance, or direction traveled by the elevator. You can assume that the elevator can hold an

unlimited number of people.

Technical Requirements

Write a discrete$-$event simulation that models the operation of the elevator$($s$)$ in the ICT building. Specifically, do the following:

Design and implement a simulation model of the ICT building elevator$($s$),$ using either C$,$ C$++,$ or Java. Parameterize your simulation reasonably, and document any additional

assumptions you make. Instrument the simulator adequately so that you can collect the timing information required for your analysis of results.

For the single$-$elevator scenario, implement any two of FCFS$,$ SSTF$,$ or Linear Scan as possible scheduling algorithms. Conduct a simulation experiment to see which of these

scheduling algorithms is best, in terms of average user$-$perceived response time. Use only this best scheduling algorithm in your subsequent simulation experiments.

For $N=1,$ conduct simulation experiments that evaluate any two of the suggested elevator idling policies $($i$.$e$.,$ Stay, Bottom, Middle, Top$)$ to see the impact, if any, on the user$-$

perceived response time. Choose the best such idling policy for your remaining simulation experiments.

Increase the number of elevators from $N=1$ to $N=2.$ Show the impact, if any, on the user$-$perceived response time. Justify any additional assumptions or design decisions that

you make.

When you are finished, please submit your solution in electronic form to your TA$.$ Your submission should include the source code for your simulation program, a brief user manual

describing how to compile and use your simulator, and a description of the results generated using your program. Please remember that assignments are to be done individually, and

submitted to your TA on or before the stated deadline. The penalty for late submissions is $4$ marks per day $($or portion thereof$)$ beyond the deadline.