مبادئ حساب التكاليف الصناعية

ISE 304 – Principles of Industrial Costing Quiz 2 Sample

  1. A single-worker cleaning operation follows a machining operation in a specific product manufacturing line. A work sampling study has been ordered to establish the standard time for this operation. A total of 1,360 random observations have been collected, with the following breakdown:
    Element Count
    Submerge part in oil 602
    blow with high pressure air 591
    Worker not in site 64
    Idle 103

    The study was conducted over three days, with a single shift of 6.5 hours. During the study, 1,000 products were produced. The cleaning operation has been rated at 95%, and the company implements a 20% PFD allowance.

    1. Compute the standard time for the cleaning operation.
    2. Compute the direct labor cost associated with the production of 2,000 parts if the labor wage is 10 riyals per hour.
  2. In an assembly line, product testing is the slowest operation in the line. The standard time to test a single product is 3.5 minutes. The production department has received a rush order of 4,500 products that have to be delivered in five days. The testing stage employs 7 workers; and the work day consists of 7 hours. The regular worker wage is 20 riyals per hour. Any hour of overtime is paid double the regular hourly wage. What is the testing direct labor cost associated with this order?
  3. The industrial engineer in the Gulf TV Antennas Factory in Dammam needs to establish the standard time for a certain assembly operation. He has initiated a time study and determined that this assembly operation has four elements. Initially, he took 3 observations for each element in order for him to determine the sample size. The observations are shown in the following table, where the times are in seconds:
     

    Elements
    Observations 1 2 3 4
    1 5.3 3.0 3.7 4.0
    2 4.4 2.8 5.3 4.4
    3 3.7 1.7 4.3 2.7
    Rating 90% 100% 105% 100%
    1. He has established that an error E = 1.5 seconds will be adequate for this study.
      1. Find the required sample size for each element using the formula
        sample size formula
        For α = 0.05, t0.025,2 = 4.303. Maintain 3 decimal places.
      2. Take the necessary additional observations from the following table and compute the standard time based on a PFD allowance of 11%:
         

        Elements
        Observations 1 2 3 4
        4 6.4 2.7 3.9 2.9
        5 4.3 3.0 3.7 3.7
        6 3.0 1.6 2.4 3.9
        7 3.8 3.3 3.7 2.5
        8 3.7 1.2 3.5 3.9

        If observations are needed more than what have been given, use all the observations listed above.

    2. The factory operates a single shift of 6.5 hours from Saturday to Wednesday and one shift of 5 hours on Thursday. In rare circumstances, the plant can run overtime. The workers in the plant are paid a salary of 3,500 riyals per month. Any overtime hour will be paid the double hourly wage. Assume that there are 4 weeks in a month. The production planning department has received an order of 12,000 units that will be started on next Tuesday and delivered early the following Sunday. If two workers are assigned to the assembly stage explained above, compute the associated direct labor cost.

Instructor: Dr Muhammad Al-Salamah