You are given a network diagram (see Figure 1) that represents the turnaround operation of an aircraft. The list of activities (nodes) of this operation is explained and given in Table 1 below. Durations of activities (i.e. nodes) in Table 1 represent the deterministic activity times of aircraft ground operation. Durations of activities given in Table 2 represent the stochastic service times of ground operational activities. Based on the given information, please answer ALL the following questions: (i) According to the deterministic PERT model given in the lecture, please calculate for each node in Figure 1 (and Table 1) the following time attributes: ES, EC, LS, LC and Slack times. Please also identify the critical path. (20 marks) (ii) Please discuss your results from the first question: based on your calculation from the deterministic PERT model, are there any other paths that may cause potential delays (i.e. risks) in turnaround? If any, how would you plan to improve the OTP (on-time performance) of this flight?) Please apply the stochastic PERT model by using information given in Figure 1, Table 1 and Table 2. Please arrange your results in the form of Table 3 (given below), and fill those columns in Table 3. (10 marks) (iv) Based on the results from the stochastic PERT model, please discuss your results and analyse the risk of delays for this ground operation. For example, what if the scheduled turnaround time is 45 minutes, what’s the risk of delays? How about 50 minutes turnaround? How would you improve the reliability of this operation based on your analyses? (10 marks) (v) The airline is planning to introduce new cabin services and improve on-board entertainment systems. However, this increases the service time of activity number 6 (i.e. Cabin cleaning & service preparation in Table 1) from 15 minutes to 25 minutes. The stochastic distribution parameters are given in Table 2 (see the last row of Table 2, labelled by What would you suggest to the Executive General Manager of Cabin Services of this airline in this business case? Airline networks are profoundly influenced by commercial interests, market sizes, airline fleets (and other resources) and strategic plans of airlines. This causes complexity to airline strategic schedule planning and subsequent airline operations and disruption management. In this essay question, please discuss the issue of airline network complexity from the following perspectives by providing your own examples to highlight the complexity: (1) Air passenger connections, commercial interests, and markets served in a network. (Note: you may like to consider different types of networks and pax connections.) (10 marks) (2) Aircraft routing and aircraft utilisation. (10 marks) (3) Crew pairing, rostering, and crew utilisation. (10 marks) (4) Schedule robustness and disruption management: the forming of network complexity and the joint influence on airline operations. (Note: (a) consider how this complexity is created during schedule planning, and how the complexity as a whole influences airline operations; (b) explain how you can improve schedule robustness and operational reliability by dealing with network complexity both from scheduling and operational perspectives.)