OPERATION MANAGEMENT
ASSIGNMENT – 1 Forecasting
Note: Use MS Excel and submit one file with 7 tabs, one for each of the following questions.
The monthly sales of the year 2019 for Yazici Batteries, Inc., were as follows:
| Month | 2019 Sales |
| January | 20 |
| February | 21 |
| March | 15 |
| April | 14 |
| May | 13 |
| June | 16 |
| July | 17 |
| August | 18 |
| September | 20 |
| October | 20 |
| November | 21 |
| December | 23 |
1. Plot the monthly sales.
2. Forecast January 2020 sales using the Naive method
3. Forecast January 2020 sales using a 3-month moving average.
4. Forecast January 2020 sales using a 6-month weighted average using .1, .1, .1, .2, .2, and .3, with the heaviest weights applied to the most recent months.
5. Forecast January 2020 sales using exponential smoothening where α = .3 and a September forecast of 18.
Bonus Questions
6. A trend projection using a regression equation Y = a + bX where is X is the month number. (example: for June, X = 6)
7. With the data given, which method would minimize the error in forecast?
