CPM solution


                                             Activity

                                             Duration

                                                ET

                                                LT

                                                TF

                                             Training

                                                 6

                                         initial activity

                                                 0

                                          LT(3) = 26-8=18

                                          LT(4) = 16-7=9

                                                 9

                                               9-0-6

                                                 3

                                            Purchasing

                                                 9

                                         initial activity

                                                 0

                                          LT(3) = 26-8=18

                                          LT(4) = 16-7=9

                                                 9

                                               9-0-9

                                                 0

                                            Production

                                                 8

                                           ET(1) = 0+6=6

                                           ET(2) = 0+9=9

                                                 9

                                         LT(6) = 38-12=26

                                                26

                                              26-9-8

                                                 9

                                          Quality control

                                                 7

                                           ET(1) = 0+6=6

                                           ET(2) = 0+9=9

                                                 9

                                         LT(5) = 26-10=16

                                                16

                                              16-9-7

                                                 0

                                            Assembling

                                                10

                                          ET(4) = 9+7=16

                                                16

                                         LT(6) = 38-12=26

                                                26

                                             26-16-10

                                                 0

                                           Transporting

                                                12

                                          ET(3) = 8+9=17

                                         ET(5) = 16+10=26

                                                26

                                         terminal activity

                                                38

                                             38-26-12

                                                 0


Critical path:

Purchasing → Quality control → Assembling → Transporting