Page 56 - DCOM303_DMGT504_OPERATION_RESEARCH
P. 56

Unit 3: Linear Programming Problem – Simplex Method




          Therefore,    Z = C X                                                                 Notes
                             B  B
                          = 0 + 0 + 0
                          = 0
          Step 4: Second iteration of Simplex Method.

              BV        CB       XB        Y1       Y2        S1       S2      Min.
                                                                               Ratio
               y2       3       1/1 = 1   1/1 = 1   1/1 = 1   --       --       --
               S2       0      4-1(1) = 3   3-1(1) = 2   1-1(1) = 0   --   --   --
                                 Zj        3         3
                                 Cj        2         3
                                Zj – Cj    1         0

          Therefore,    Z = C  X
                             B  B
                          = (3 × 1) + (0 × 3)
                          = 3

          Therefore, Maximum value of ‘Z’ = 3

                Example:
          Maximise ‘Z’ = 4x  + 3x           [Subject to constraints]
                        1    2
                    2x  + x   30
                     1   2
                    x  + x   24
                     1   2
          Where,      x , x   0            [Non-negativity constraints]
                      1  2
          Solution:
          Step 1: Convert the inequalities into equalities adding slack variables.
                2x  + x  + x  = 30
                  1  2   3
                 x  + x  + x  = 24
                  1  2   4
                 Where x  and x  are slack variables.
                       3    4
          Step 2: Fit the data into a matrix form.

                    Y 1  Y 2  S 1  S 2     x 1  
                     x  x  x  x      x     30
                A      1  2  3  4    X      2     B       
                    2  1   1  0      x      24 
                                     3   
                     1  1  0  1      x 4  
          Step 3: First iteration of Simplex Method.

              BV        CB       XB        Y1       Y2     S1    S2      Min. Ratio
               S1        0        30       2               1     0     30/2 = 15 (KR) ?
               S2        0        24       1        1      0     1        24/1 = 24
                                  Zj       0        0
                                  Cj       4        3
                                Zj – Cj    -4       -3
                                          ( KC)





                                           LOVELY PROFESSIONAL UNIVERSITY                                   51
   51   52   53   54   55   56   57   58   59   60   61