Question

1. Consider the two processes shown below. Which one will have on average the higher total production outcome (i.e., total number of products produced in a given time period)?

1. Process A
2. Process B
3. On average, they will have the same total production outcome.

2. What happens in Process B above if the buffer size increases from 2 to 10?

1. Throughput time increases
2. Throughput time decreases
3. Starving increases
4. Throughput rate decreases
5. Nothing changes 3. Chef Chati works at the kitchen of a Thai restaurant on the MIT campus. The restaurant is open for lunch from 12-1:30. If she works alone she prepares 300 lunches during that time period. If she has a helper, they prepare 500 lunches. What is the percent change in productivity of the kitchen when she adds an assistant?
   1. 16.7%
   2. -16.7%
   3. -133%
   4. 66.7%
   5. None of the above 4. On a typical weekday in January, 4200 customers visit the local Wal-Mart. It is estimated that, on average, there are 350 customers in the store. Assuming that the store is open 14 hours a day, how much time does the average customer spend in the store?
      1. 7 min
      2. 20 min
      3. 14 hours
      4. 1.167 hours
      5. None of these

Answer 1

1) Option C.

The average capacity of both the processes is 3.5 products per hour (3+4 / 2) and (1+6 / 2). The probability is also the same for both, that is , 50%. Hence the production outcome will be the same for both.

2) Option B.

Since the average products processed increases from 3.5 to 6 per hour, the overall time decreases to produce.

3) Option D.

The average time in first case is 3.33 lunches per minute (300/90) and in the second is 5.55 lunches per minute (500/90). Hence, the percentage increase from first case to second is 66.7%

4) Option D.

Applying Little's law

Average time = Average customers in store / Average customers per day (4200/14)

=> 350 / 300

=> 1.167 hours