Hertentamen Operations Management (50 punten)
Dutch Railway Company
Vraag 1, chapter 4 (12 punten)
During winter a lot of the material of the Dutch Railway company shows defects due to rain and
other bad weather conditions. As the Dutch Railway system is the most intense used Railways
in the world it is more than a necessity to get defect trains as quickly as possible on track again.
To improve their maintenance production line they focus on the way the aircraft industry
organized here maintenance.
The maintenance of the ‘Sprinter’ a local train type contains the following activities, along with
their time estimates for completion
Activity Times estimates (hours) Immediate
predecessor
a m b
A 1 3 6
B 2 5 6 A
C 3 3 5 D
D 6 11 13 A
E 3 5 11 D
F 6 7 15 B,C
1a. Bereken de doorlooptijd van het reparatieproces en de afwijking per activiteit (5
punten)
1b. Teken de netwerkplanning (3 punten)
A–B
A- D – C
D- E
B en C – F
Optimistic 1 + 2 + 6 + 3 + 6 = 18
Most likely 3 + 5 + 11 + 5 + 7 = 31
Pessimistic, 6 +6 + 13 + 11 + 15 = 51
activity ET variatie
A 0,69 3,16
B 0,45 4,67
C 0,11 3,33
D 1,37 10,5
E 1,77 5,67
F 2,25 8,17