PL EN


2014 | 178 | 190-205
Article title

Porównywanie efektywności prognoz ex post wielkości sprzedaży w pewnym przedsiębiorstwie wyznaczonych za pomocą rozkładu gamma i modeli z wahaniami sezonowymi

Content
Title variants
EN
Comparing the Effectiveness of Ex Post Forecasts of Sales in a Company Obtained by Means of Gamma Distribution and Models with Seasonal Adjustments
Languages of publication
PL
Abstracts
EN
Main aim of the article was comparison of sales forecasts effectiveness in a company. In the first stage time series representing sales were selected with respect to presence of seasonality and consistency with gamma distribution. Two types of statistical tests were used: F test (seasonality) and nonparametric Locke tests (compatibility with gamma distribution). In the next step ex post forecast were computed by means of linear trend model with seasonality and gamma distribution (on the level of median of theoretical distribution). Effectiveness of forecasts was compared on the basis of chosen coefficients of forecasts errors. Forecasts obtained be means of gamma distribution turned out to be better in all considered aspects
Year
Volume
178
Pages
190-205
Physical description
Contributors
References
  • Całczyński A. (red.), 2000: Elementy badań operacyjnych w zarządzaniu. Tom 1. Radom.
  • Czerwiński Z., Guzik B., 1980: Prognozowanie ekonometryczne. PWE, Warszawa.
  • Dittman P., 2004: Prognozowanie w przedsiębiorstwie. Oficyna Ekonomiczna, Kraków.
  • Locke C., 1976: A Test for the Composite Hypothesis that Population Has a Gamma Distribution. "Communications in Statistics", 4, s. 351-364.
  • Sarjusz-Wolski Z., 2000: Sterowanie zapasami w przedsiębiorstwie. PWE, Warszawa.
  • Shapiro S.S., Chen L., 2001: Composite Test for the Gamma Distribution. "Journal of Quality Technology", Vol. 33, No. 1, s. 47-59.
  • Tadikamalla P.R., 1984: A Comparison of Several Approximations to the Lead Time Demand Distribution. "International Journal of Management Science", Vol. 12, No. 6, s. 575-581.
  • Zeliaś A., 1997: Teoria prognozy. PWE, Warszawa.
Document Type
Publication order reference
Identifiers
ISSN
2083-8611
YADDA identifier
bwmeta1.element.desklight-20e4bd6c-22c5-4a51-a726-b21f9a5fbcb8
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