This model makes the same assumptions as in
the first model with a few additions and exceptions. The parking
lot now has dimensions measured in feet instead of using a grid-like
mechanism. We also assumed that we would want two cars to be able
to pass each other in an aisle
The sets used in this model were:
I, Number of rows in the parking lot
J, Number of spaces in each row in the parking
lot
The variables used in this model were:
X(I,J) binary variable - 1 if a parking space, 0 otherwise
Z - total number of spots in the lot
LASTJ the last parking space in a row - 8
LASTI the last row in a lot - 8
AISLEWIDTH the width of the driving aisle -16 feet
LENGTHI the length of the parking lot - 128 feet
WIDTHJ the width of the parking lot - 64 feet
SLENGTH the length of a parking spot - 16 feet
SWIDTH the width of a parking spot - 8 feet
Objective Function - maximize the total number of spots in the parking lot.
Subject to the following constraints:
-Lanes 1-3: ensure that there is a lane behind each parking row;
-IntLanes 1-5: ensure that every driveway meets two other driveways;
-Corners 1-4: ensure only one spot in corners of lot;
-Aisles 1-2: ensure that there is a full driving
aisle on all sides of the parking lot.
This solution is more valid than the previous model since an actual
measurement system is used. The measurements used are representative
of a real parking lot to ensure a "real life" answer.
However, the parking space measures used would only fit small
to medium-sized vehicles. The model also allows sufficient space
for cars to turn into stalls. Vehicles can now turn corners in
aisles wide enough for two cars to pass. These aisles are placed
vertically alongside a column of stalls. The optimum solution
for the chosen measurements is 28 parking stalls.
We are aware that our model is still not quite
adequate for a real world application. The issue of accessibility
of all vehicles to an aisle needs to be addressed as well as the
need for an entrance to the parking lot. One major drawback of
this model is that aisle widths are multiples of the parking stall
length and width. A more realistic model would allow for any width
of driving aisles. However, we chose to bypass this issue due
to its complexity.