Table 7. Hospitals, bus ambulances, and their capacities
Hospital
|
Capacity
|
Number of Bus Ambulances
|
Capacity of each Bus Ambulance
|
Gaziantep
|
200
|
2
|
20
|
Aleppo
|
200
|
2
|
20
|
The objective is to minimize the total latency (time taken for each victim to reach a hospital) while ensuring that the capacities of ambulances and hospitals are not exceeded. It is assumed that the ambulances travel with an average speed of 40 km/h.
1. Design, explain, and implement a feasible solution to solve this problem. (Implement your algorithm in Microsoft Excel.)
2. Describe the characteristics of your solution, including the routes and schedule of each ambulance, the latest service completion time among all victims, and the total latency of victims.
3. Identify any inefficiencies in your solution. If present, suggest improvements.
4. Evaluate the fairness of your solution. Define what fairness means in this context and explain how your initial solution could be revised to address fairness considerations.
Section 4 – Warehouse and Inventory Management
ABC runs several retail outlets in China. The firm buys its products from a limited number of suppliers and stores them in a warehouse located near Shanghai. They expect to sell 3,000 boxes of canned tomatoes during the next year. The current annual interest rate is 30%, and placing an order costs ¥50.
The supplier offers a box at ¥3, if the amount bought is less than 500 boxes. The price is reduced by 1% if 500 – 2,000 boxes are ordered. Finally, if more than 2,000 boxes are ordered, an additional 0.5% discount is applied.
1) Using this information, determine the optimal order size for the canned tomatoes.
These boxes will be stored in pallets, which are then put onto the shelves of the racks in the warehouse. The company is using pallets with dimensions of 110 x 110 cm. Each pallet can carry one part, and each shelf can carry one pallet. Due to the physical constraints, at most 5 shelves can be stacked on each rack.
To ease the movement of forklifts between the aisles, the management would like to separate the racks with 3m corridors and leave a 4m-wide central aisle between the two sections of the racks. A sample design would be as follows:
Based on the order quantity you determined above, help the company in designing the warehouse dedicated to this part.
2) How many storage locations are needed in horizontal and vertical axes, and accordingly how much space is needed in both axes such that this design fits?
3) Show the values you have found on a sketch of the warehouse and explain to the management the design and the total area needed.
Section 5 – Machine Scheduling
Consider a manufacturing plant, which is dedicated to producing a product that is provided to a car manufacturing company to be used in the assembly process. The production stages are depicted in the following figure:
There are two main production stages. In the first stage, first four machines (M1-M4) work in parallel to process 12 different parts and a work-in-process (WIP), which includes the processed parts 1-12, is obtained as a result of the first stage. In the second stage, there is only one machine, M5, which takes these processed parts and an external part (Part 13) as input to produce the final product. The processing times of the first 12 parts, in minutes, are as follows:
Table 5. processing times of parts 1 – 12 in machines 1 – 4
Parts
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
Processing times
|
6
|
6
|
5
|
4
|
5
|
2
|
8
|
6
|
10
|
10
|
5
|
4
|
Part 13 is supplied by an external supplier every 17 minutes. The process at M5 can begin as soon as both Part 13 and WIP are ready. Then the time required at M5 to produce the final product is 20 minutes.
The final product is then loaded to an automatic guided vehicle (AGV) to be delivered to the assembly line. It is essential that the AGV departs as soon as possible to avoid stoppages in the assembly line.
1) What is the objective of this manufacturing plant in this process, why?
2) How are the problems in the first stage and in the second stage expressed using scheduling notation?
3) Using an appropriate method, advise a production plan. Explain the reasons of the selection of the method you use, comment on utilisation of the machines and any inefficiencies if applicable.
4) Assume that the car manufacturing company has asked whether the final product can be delivered to the assembly line more frequently. The engineering team then advised that there may be improvements in the processes, which would shorten the processing times of the parts that are processed in machines 1-4. Thinking about the request of the car manufacturing company, which parts would you suggest the engineering team should focus and aim for reduction in the processing times? Explain the reasons.