2. Consider the data in the file “Soft_Fruit_Spreads_Distribution-Routing.xls” on Moodle. The data describes the coordinates of the locations of the retailers and their demands, coordinates of the location of the distribution centre, capacity of the vans, and the number of vans available at the distribution centre.

Set up the Excel spreadsheet and optimisation models on Evolver and explain clearly the implementation of the decision variables, the constraints, and the fitness function. Indicate which Evolver solving method you have used to solve the problem and the initial solution you have used.

Solve the problem to find the best minimum distance travelled by experimenting with the following parameters:

(a) Population size: 50

(b) Crossover and mutation rates:

(i) Crossover rate = 0.8, mutation rate = 0.01.

(ii) Crossover rate = 0.9, mutation rate = 0.02.

(iii) Crossover rate = 0.6, mutation rate = 0.5.

(iv) Crossover rate = 0.3, mutation rate = 0.8.

(c)The stopping criterion for all the experiments should be set to 20000 generations.

For each combination provide a detailed description of the best solution: total distance travelled, set of routes to be travelled by the vans, computation time required to generate the best solution. For each van, specify the retailers to visit and the order in which they have to be visited.

Provide a graphical illustration of the routes of the vans for the initial solution and the overall best solution.

Data Link