written 7.7 years ago by |
Let n=7, Profits(p1, p2. ….p7)={3, 5, 20, 18, 1, 6, 30} Deadlines(d1, d2,….d7)={1, 3, 4, 3, 2, 1, 2} The feasible solution and their values are given below.
Sr. No | Feasible Solution | Frequenting Sequence | Value |
---|---|---|---|
1 | (1,2) | 1,2 or 2,1 | 8 |
2 | (1,3) | 3,1 | 23 |
3 | (1,4) | 4,1 | 21 |
4 | (1,5) | 5,1 | 4 |
5 | (1,6) | 6,1 | 9 |
6 | (1,7) | 7,1 | 33 |
7 | (2,3) | 3,2 | 25 |
8 | (3,4) | 4,3 | 38 |
9 | (4,5) | 5,4 | 19 |
10 | (5,6) | 6,5 | 7 |
11 | (6,7) | 7,6 | 36 |
12 | (1) | 1 | 3 |
13 | (2) | 2 | 5 |
14 | (3) | 3 | 20 |
15 | (4) | 4 | 18 |
16 | (5) | 5 | 1 |
17 | (6) | 6 | 6 |
18 | (7) | 7 | 30 |
Consider the jobs in the non-increasing order of profits subject to the constraint that the resulting job sequence J is a feasible solution.
In the example considered before, the non-increasing profit vector is
30 | 20 | 18 | 6 | 5 | 3 | 1 | 2 | 4 | 3 | 1 | 3 | 1 | 2 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
p1 | p2 | p3 | p4 | p5 | p6 | p7 | d1 | d2 | d3 | d4 | d5 | d6 | d7 |
i. Now we start adding the job with J = 0 and Σ i ej Pi= 0.
ii. Job 7 is added to J as it has the largest profit and thusJ = {7} is a feasible one.
iii. Now job 3 is considered. The solution J = {3, 7} is a feasible one with processing sequence (7, 3).
iv. The next job, Job 4 is considered. The solution J = {3, 4, 7} is a feasible one with processing sequence (3,4,7).
v. Finally, the next job, Job 6 is considered. The solution J = {3, 4, 6, 7} is a feasible one with processing sequence (3,4, 6,7).
vi. Thus we have J = {3,4, 6, 7} is optimal solution with value 74.’