Assignment Instructions:

1. You can use any resources to do this assignment, i.e. this is an open-book assessment. All questions in this assignment paper are compulsory. The total mark is 100%.
2. NO peer discussions; you CANNOT discuss this assignment with your classmates or friends by any media (on-line or off-line).
3. DO NOT copy and past from any sources, including textbooks. All submissions will go through Turn-it-in checks.
4. Prepare your answers by word-processing software and other software if required, e.g. Excel or SPSS. NO hand-written answer sheets allowed.
5. Do not expect to be able to answer all questions, but do try your best! Remember that you can do research (online or off-line) to answer questions. Wish you luck. ^_^

Submission Instruction:

1. Assignment deadline is available on Moodle. 10% off your original mark each day if your submission is late on Moodle without prior approval from Aviation Office.
2. You are required to submit the following:

• A soft copy: submit a soft copy on Moodle by the deadline. The soft copy should be in the form of a single PDF file that includes all your works. Name your file by: Surname_StudentID.pdf, e.g.
  WU_z123456789.pdf. You can print your Word file into a PDF form on a Mac (built-in function) or on Windows (you may need a PDF ‘printer’ for your Windows system; google for more information).

Question 1. Airline Network Modelling – PERT Model (100 marks)

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 operation activities. Based on the given information, please answer ALL the following questions:

(i) According to the deterministic PERT model, please calculate for each node in Figure 1 (and Table 1) the following time attributes: ES, EC, LS, LC and Slack times. Please prepare your answers in the format of Table 3.6 of the textbook (p82). Please also identify the critical path. (30 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? (20 marks)

(iii) Please apply the stochastic PERT model (§3.3.4 of the textbook) 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.
(20 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 time? How would you improve the reliability of this operation based on your analyses? (15 marks)

(v) The airline is planning to introduce new cabin services and improve on-board entertainment systems. However, this change may increase the service time of activity number 6 (i.e. Cabin cleaning & service preparation in Table 1) from 15 minutes to 25 minutes (highlighted in Table 2). The stochastic distribution parameters of activity number 6 are given in Table 2 (see the last row of Table 2, labelled by ‘6 (new)’). Please do scenario studies on this change and
evaluate the potential impacts and risks this service change may cause to future ground operations. What would you suggest to the Executive General Manager of Cabin Services of this airline for this business case? For or against and why? (15 marks)