$\backslash$table$[[$Year$,$Quarter,Sales, R$],[2020,$Q$1,300000],[,$Q$2,350000],[,$Q$3,480000],[,$Q$4,420000],[2021,$Q$1,330000],[,$Q$2,390000],[,$Q$3,540000],[,$Q$4,480000],[2022,$Q$1,360000],[,$Q$2,450000],[,$Q$3,600000],[,$Q$4,540000],[2023,$Q$1,390000],[,$Q$2,480000],[,$Q$3,720000],[,$Q$4,600000]]$

REQUIRED:

$4\mathrm{.}1.$Discuss any three $(3)$ strategic importance of demand forecasting in supply chain and operations

$(4$ Marks$)$

management.

$4\mathrm{.}2.$ Using the quarterly sales data extracted by the demand planner, prepare the $3-$quarter moving$-$

$(4$ Marks$)$

average $(3$QMA$)$ forecast for each of the fourteen quarters spanning from Q$42020$ to Q$12024.$ Ensure that your calculations are clearly presented in a table, with all forecast values displayed.

$4\mathrm{.}3.$ Using the quarterly sales data extracted by the demand planner, prepare the simple exponential

$(4$ Marks$)$

smoothing $($SES$)$ forecast for each of the sixteen quarters spanning from Q$22020$ to Q$12024.$ Assume that the forecast for Q$12020$ is R$300000$ and use a smoothing constant $($a$)$ of $0\mathrm{.}5.$ Ensure that your calculations are clearly presented in a table, with all forecast values displayed.

$4\mathrm{.}4.$ Calculate the Mean Absolute Percentage Error $($MAPE$)$ for both the $3$QMA and SES forecasts over

$(6$ Marks$)$

the thirteen quarters from Q$42020$ to Q$42023.$ Show the detailed calculations for obtaining the MAPE values and round off answers to two decimal places.

$4\mathrm{.}5.$Based on the results obtained in question $4\mathrm{.}4,$ which of the candidate forecasting methods should be selected by the demand planner?

$(2$ Marks$)$