Methus Detchusananart and Munchuporn Techachaianun
12 November 2014
Multi-Intervention Aggregate-Disaggregate Forecasting Model
Advisor: Asst.Prof.Seeronk Prichanont, Ph.D.
Co-Advisor: Asst. Prof.Krung Sinapiromsaran, Ph.D.
Cash Out
Over cash inventory
To optimize the amount of cash notes in the machine
Luther Simjian
John Shepherd-Barron
Patterns of Time Series
To predict the value at the present time using the value at the previous time.
EQUATION AR(p)
\[ X_t = \Phi_1 X_{t-1} + \Phi_2 X_{t-2} + ... + \Phi_p X_{t-p} + \varepsilon_t \]
where \( \varepsilon_t \) is independent identically distributed (iid) with Normal Distribution of mean 0 and constant variance \( \sigma_\varepsilon^2 \)
“Past Error”
EQUATION MA(q)
\[ X_t = \varepsilon_t + \theta_1 \varepsilon_{t-1} + ... + \theta_q \varepsilon_{t-q} \]
where \( \varepsilon_t \) ~ \( N(0,\sigma_\varepsilon^2) \)
EQUATION ARMA(p,q)
\[ X_t = \Phi_1 X_{t-1} + ... + \Phi_p X_{t-p} + \varepsilon_t + \theta_1 \varepsilon_{t-1} + ... + \theta_q \varepsilon_{t-q} \]
For example ARMA(1,1)
\[ X_t = \Phi_1 X_{t-1} + \varepsilon_t + \theta_1\varepsilon_{t-1} \]
From ARMA(p,q)
\[ X_t = \Phi_1 X_{t-1} + ... + \Phi_p X_{t-p} + \varepsilon_t + \theta_1 \varepsilon_{t-1} + ... + \theta_q \varepsilon_{t-q} \]
\[ X_t - \Phi_1 X_{t-1} - ... - \Phi_p X_{t-p} = \varepsilon_t + \theta_1 \varepsilon_{t-1} + ... + \theta_q \varepsilon_{t-q} \]
\[ (1-\Phi_1 B - ... - \Phi_p B^p) X_t = (1 + \theta_1 B + ... + \theta_q B^q)\varepsilon_t \]
\[ \Phi(B)X_t = \theta(B)\varepsilon_t \]
\[ ARIMA(p,d,q): \Phi(B)(1-B)^d X_t = \theta(B)\varepsilon_t \]
EQUATION Holt-Winters(\( \alpha \))
\[ F_{t+1} = \alpha X_t + (1-\alpha)F_t \]
where \( \alpha \) is a smoothing constant and \( 0 \leq \alpha \leq 1 \)
ARMA
ARIMA
Exponential smoothing
| Subsequence | Suitable model | MAPE | Rank | Forecast value at t = |
|---|---|---|---|---|
| 1 | Additive model | 0.1032391 | 6 | 33,34,35,36,… |
| 2 | ARIMA(0,1,0) model | 0.0960504 | 5 | 33,35,37,39,… |
| 3 | Exponential Smoothing | 0.2024615 | 10 | 34,36,38,40,… |
| 4 | Exponential Smoothing | 0.1315447 | 7 | 34,37,40,… |
| 5 | Exponential Smoothing | 0.1458527 | 8 | 35,38,41,… |
| 6 | ARIMA(0,1,0) model | 0.08148158 | 2 | 33,36,39,… |
| 7 | ARIMA(0,1,0) model | 0.08949418 | 4 | 33,37,41,… |
| 8 | ARIMA(0,1,0) model | 0.08702252 | 3 | 34,38,42,… |
| 9 | ARIMA(0,1,0) model | 0.0771577 | 1 | 35,39,43,… |
| 10 | ARIMA(0,1,0) model | 0.17808997 | 9 | 36,40,44,… |
Use the same distribution of data as the previous period
EX. For week 9, use the distribution from week 1 and 5