Single Machine Total Weighted Tardiness Problem

Alright, this python code is purposed to solve SMTWTP (Single Machine Total Weighted Tardiness Problem) using Genetic Algorithm.

Genetic Algorithm in this project

You can take a look the GA implemented inside a file: genetic_algorithm.py

On this project, this is how the GA mechanism works:

1. Generate Random Solutions

• Firstly, this program will take a SMTWTP problem as an input from an excel file: data/case_1.xls (usual SMTWTP problem table)
• and will generate random solutions of the given problem
• the first solutions generated are 6 in total (why 6? because following the total of the projects)

2. Calculate Fitness Function

• calculating the fitness function (total weighted tardiness) as per SMTWTP formula

3. Selection Process

• the selection process will take two chromosomes as parents randomly and prepared for crossover
• after selecting the parents, the crossover is executed. After the crossover, this program will sort the 2 best candidate (chromosome) and will be the next gen candidate, this method is called as "Elitism"

4. Crossover Process

• in this process the parent's gene will be swapped to each other
• the genes that swapped are the last two genes of the parents. Can see the example on the table below

  Example	Chromsome
  Chromosome A:	A F D C (B E)
  Chromosome B:	C A B F (E D)
  New Chromosome 1:	A F D C E D
  New Chromosome 2:	C A B F B E

5. Mutation Process

• mutation process will take a look if there's a same gene in a chromosome
• if there's a same gene, one of it will be replaced to a new unique gene which hasn't in the chromosome

  Example	Chromsome
  New Chromosome 1:	A F D C E D
  New Chromosome 1 (mutated):	A F D C E B
  New Chromosome 2:	C A B F B E
  New Chromosome 2 (mutated):	C A B F D E

Input & Ouput

• The program input as stated above is from the excel file data/case_1.xls

• Expected output in terminal:
  

The Files

• main.py
• data/case_1.xls
• genetic_algorithm.py
• helper.py
• Just ignore the others

Usage

python main.py