Page 38 - Proceeding The 2nd International Seminar of Science and Technology : Accelerating Sustainable Innovation Towards Society 5.0

nd
The 2 International Seminar of Science and Technology
“Accelerating Sustainable innovation towards Society 5.0”
ISST 2022 FST UT 2022
Universitas Terbuka
Single Exponential Smoothing calculation can be written in
Equation 1, where Ft+1 = Forecast for period t+1, Xt = Real value
of period-t, α = The weight representing the smoothing constant
(0< α<1), Ft-1 = forecast for period t-1

+1 = + (1 − ) −1 (1)

2.3 Forecasting Error Measurement
Measurement of forecasting errors is done by comparing the results
of forecasting with the reality that happened. A model is said to have
good and accurate forecasting results if it generates a small error
value [14]. The equation formula for finding the MAPE error value is in
Equation 2, where = Actual data in period-t, = Forecasting data in
′

period-t, = Number of data used.

′
1 | − |
MAPE = ∑ =1 100% (2)

3 RESULT
3.1 Descriptive Analysis
Based on Figure. 1, Indonesia's gold jewellery demand in 2010-2020,
where the highest demand was in 2018 with a value of 41.9 tons, an
increase of 3.3 tons from the previous year (in 2017). According to
data from the world gold council, Indonesia's gold demand in 2018
was ranked 6th as the country with the world's largest gold demand
after Russia. Meanwhile, the lowest gold demand occurred in 2020,
which was 20.9 tons. According to data from the World Gold Council,
the decline in demand for gold in the jewellery sector experienced a
significant decline in the 1st quarter of 2020. The decline in demand
for gold jewellery in 2020 is not only in Indonesia but also in several
other countries. This is because local gold prices have skyrocketed so
that consumers are unable to absorb the existing supply of jewellery.
And the main reason is the Covid-19 pandemic [15].

ISST 2022 – FST Universitas Terbuka, Indonesia 17
International Seminar of Science and Technology “Accelerating Sustainable
Towards Society 5.0