Advanced Risk and Uncertainty Management Tunnel Boring Machine

Question: Dicuss about the Advanced Risk and Uncertainty Management for Tunnel Boring Machine. Answer: Probability of choosing Tunnel Boring Machine is 0.5 and probability of choosing Drill and Blast method is 0.5. Probability of the ground being unstable is 0.33. Therefore, the probability of choosing the Tunnel Boring Machine and the ground is unstable is 0.5 * 0.33 = 0.165 The estimated construction cost for this combination (combination 1) is $300000000 * 0.165 = $ 49500000. Estimated construction time in months = 45* 0.165 = 7.425 months Probability of ground being stable is 0.67. Probability of ground being consistent = 0.15. Probability of choosing a stable and consistent ground under the method of Tunnel Boring Machine (combination 2) = 0.5* 0.67 * 0.15 = 0.05025 Estimated cost of construction is $ 230000000 * 0.05025= $11557500 Estimated time in months = 34 * 0.05025 = 1.7085 Probability of the ground being significant water ingress is 0.3. Probability of choosing Tunnel Boring Machine construction for stable ground and significant water ingress (combination 3) = 0.5 *0.67 * 0.3 = 0.1005 Estimated cost for the construction is $ 250000000 * 0.1005 = $25125000 Estimated time in months is 40 * 0.1005 = 4.02 Probability of the ground being dry but utilities obstacles is 0.55 Probability of choosing Tunnel Boring Machine construction for stable ground and dry but utilities obstacles (combination 4) is 0.5 * 0.67 * 0.55 = 0.18425 Estimated construction cost = 0.18425 * $250000000 = $ 46062500 Estimated time of construction in months = 0.18425 * 40 = 7.37 Probability of choosing Drill and Blast = 0.5 Probability of choosing unstable ground = 0.33 Probability of choosing Drill and Blast and unstable ground (combination 5) = 0.5 * 0.33 = 0.165 Estimated construction cost = $280000000 * 0.165 = $46200000 Estimated construction time = 42 * 0.165 = 6.93 Probability of stable ground = 0.67 Probability of choosing consistent ground under stable ground and Drill and Blast (combination 6) = 0.15 * 0.67 * 0.5 = 0.05025 Estimated construction cost = $200000000 * 0.05025 = $10050000 Estimated construction time in months = 40 * 0.05025 = 2.01 Probability of significant water ingress under stable ground and Drill and Blast (combination 7) = 0.5 * 0.67 * 0.3 = 0.1005 Estimated construction cost = $240000000 * 0.1005=$24120000 Estimated construction time in months = 47* 0.1005 = 4.7235 Probability of choosing dry but utilities obstacles under stable ground and Drill and Blast (combination 8) = 0.5* 067 * 0.55 = 0.18425 Estimated construction cost = $230000000 * 0.18425 = $ 42377500 Estimated construction time = 48* 0.18425 = 8.844 It was seen that combination 2; i.e. choosing the process of Tunnel Boring Machine construction under the variable stable ground and consistent ground would take minimum time to complete the task. The task would be completed in 1.7085 months. This process takes the lowest time. The cost for this process is $11557500, which is the second least construction cost among all the given processes. Thus, it is best to choose this process for construction. Total cost estimate of the project is $47 M. Four work packages were identified for the project. The estimated cost for work project 1 is $7.50 M. The estimated cost for work package 2 is $ 18.00M. The estimated cost for work package 3 is $20.17M and the estimated cost for work package 4 is $4.33 M. The estimates cost for each package is computed by the formula (low + (4 * Most likely) + High) /6. The sum of Estimated cost for all the four packages was found to be $50 M. It was found that the risk involved to complete this project was $%0 M - $47 M = $3 M. The expected cost of the project is $56M. Its standard deviation is $16 M. The probability that the project cost would be over $75M is given as follows. The z score of the project cost is (75 - 56) / 16 = 1.1875 The value of P(X 1.1875) = 0.882485 The probability that the cost of the project would be over $75 M is given by 1 - P(X 1.1875) = 1- 0.882485 = 0.117515 The project would be delayed with a probability of 67%; i.e. 0.67 The P(X Z) = 0.439913 P(X Z) = 1- 0.439913 = 0.560087 The cost of the project in this would be (0.560087 * 16) + 56 = $64.96 The overall risk of the project would be $64.96 - $56 = $8.96.