ISE 303 Operations Research 1 Exam 1 Sample

  1. The Ministry of Health maintains three blood banks in Khobar. In a particular day, five public and private hospitals have requested quantities of blood bags of type A-. The blood supplies from the banks, requested blood bags by the hospitals, and the cost of blood per bag are shown in the following table:
        Hospitals  
        1 2 3 4 5 Supply
    Blood banks 1 8   6   3   7   5   20
    2 5   M   8   4   7   30
    3 6   3   9   6   8   30
                 
    Demand   25 25 20 10 20  

    In this particular day, bank 2 cannot deliver blood to hospital 2, hence the cost of transportation per blood bag is set to M (very large number) to signify a very large cost.

    Apply the least cost method to find a suitable starting basic solution for this problem.

  2. Helwani Bros Co. has contracted to supply one kind of tahina to 4 hotels in Khobar. Tahina is packed in a container of 1000 kg. Helwani operates three storehouses in the city, where all their products are stored. In one particular day, the availability of tahina in each storehouse is as:
    Storehouse Quantity
    1 60
    2 80
    3 40

    The contract requires the supply of the following quantities to the four hotels:

    Hotel Quantity
    1 35
    2 65
    3 25
    4 55

    Helwani Bros has applied an incentive scheme to new customers (hotels) by giving discounted prices on tahina. The table below gives the selling price (riyal) per unit for each combination of storehouse-hotel:

        Hotel
        1 2 3 4
    Storehouse 1 8 7 5 2
    2 5 2 1 3
    3 6 4 3 5

    As a profit-driven company, Helwani Bros seeks to meet its contractual agreement and make the largest money it can collect from the hotels.

    Without solving the problem, construct the transportation tableau equivalent to the problem faced by Helwani Bros.

  3. Eastern Region Municipality has three kinds of horizontal drilling machines. The municipality has four construction areas to supply water to new housing lands. The cost of operating a machine depends on the type of land being drilled. The equivalent transportation problem is illustrated in the following transportation tableau:
        Destination  
        1 2 3 4 Supply
    Source 1 3 7 6 4 5
    2 2 4 3 2 2
    3 4 3 8 5 3
    Demand   3 3 2 2  

    The costs are in riyal per hour of operation (assuming all the machines work the same hours).

    Starting from the northwest corner method, find the optimal solution for the transportation problem. Calculate the total cost of the optimal solution.

  4. Zain, being a new mobile operator in the Kingdom, has to construct its mobile network. To serve its anticipated customers in King Abdul Azziz airbase, KFUPM, and Saudi Aramco, Zain operation department has, as an initial stage, decided to erect 4 mobile towers in Dhahran area. Four construction companies have applied for the construction tasks. Since the constructions have to be started at the same time, a construction company can work on only one construction task. The construction costs in hundred thousand riyals are as follows:
        Company
        1 2 3 4
    Tower 1 4 6 5 5
    2 7 4 5 6
    3 4 7 6 4
    4 5 3 4 7

    Use the appropriate method to find the best assignment and calculate the corresponding total cost.

Dr Muhammad Al-Salamah
2008
Industrial Engineering
King Fahd University of Petroleum and Minerals