Abstract :
The purpose of this paper is to help solve one of the current existing issues of PT. Berkat Popok Bahagia which is SKUs being out of stock. It turns out that there are several reasons for this. The first reason is the amount of the stock of each SKU in the system differs from the amount of stock in the warehouse. The second reason is the demand from the distributors is not in sync with the sales and operational planning team, making it when the distributors order products (SKU) from the factory, the product is not available because it might not be in the production process. The third reason is the forecasting method that is currently being used is less suitable. Author compared the forecasting accuracy of each forecasting method in the top 2 SKUs of baby care category from simple moving average method, simple exponential smoothing method and exponential smoothing with trend method. The results of the forecasting accuracy is based on the MAPE value in which lower value indicates better method. The forecasting accuracy measurement result when comparing the 3 methods between the 2 SKUs are respectively 24.3% and 20.24% for simple moving average, 20.28% and 16.19% for simple exponential smoothing and 18.07% and 15.65% for exponential smoothing with trend. The results indicate that exponential smoothing with trend provides the best performance among the three which therefore author recommend this method compared to the current simple moving average method.
Keywords :
Diaper Market, Forecasting Method, Sales and Operation Planning.References :
- Shinohara, J. Henmi and N. Shibata, “Japan, U.S. diaper makers vie for growing Indonesian market,” 10 February 2023. [Online]. Available: https://asia.nikkei.com/Business/Consumer/Japan-U.S.-diaper-makers-vie-for-growing-Indonesian-market.
- Badan Pusat Statistik, “Jumlah Penduduk Menurut Kelompok Umur dan Jenis Kelamin,” 2022. [Online]. Available: https://www.bps.go.id/indikator/indikator/view_data_pub/0000/api_pub/YW40a21pdTU1cnJxOGt6dm43ZEdoZz09/da_03/1.
- Ahdiat, “Penjualan Popok Bayi di RI Tembus Triliunan Rupiah per Tahun,” 12 December 2022. [Online]. Available: https://databoks.katadata.co.id/datapublish/2022/12/12/penjualan-popok-bayi-di-ri-tembus-triliunan-rupiah-per-tahun.
- Vergidis, A. Tiwari and B. Majeed, “Business Process Analysis and Optimization: Beyond Reengineering,” IEEE Transactions on Systems, Man, and Cybernetics, Part C (Applications and Reviews), pp. 69-82, 2007.
- Gunasekaran and B. Kobu, “Modelling and analysis of business process reengineering,” Int. J. Prod. Res., pp. 2521-2546, 2002.
- Soliman, “Optimum level of process mapping and least cost business process re-engineering,” Int. J. Oper. Prod. Manage., pp. 810-816, 1998.
- Binioris, Logistics: Introduction in supply chain management., Passxalidis, Athens: Iatrikes Ekdoseis P.X, 2008.
- Fisher, “What is the right supply chain for your product?,” pp. 105-116, 1997.
- Ioannou, Management of production and services, Athens: Ath. Stamoulis Publications, 2005.
- Serdaris, I. Antoniadis and N. Tomlekova, “Supply Chain Management: A View of the Distribution Channel,” Bulgarian Journal of Agricultural Science, pp. 480-486, 2014.
- Ali and J. Boylan, “On the effect of non-optimal forecasting methods on supply chain downstream demand.,” IMA Journal of Management Mathematics, pp. 81-98, 2012.
- Makridakis, A. Andersen, R. Carbone, R. Fildes, M. Hibon, R.Lewandowski, J.Newton, E.Parzen and R.Winkler, “The accuracy of extrapolation (time series) methods: Results of a forecasting competition.,” Journal of Forecasting, pp. 111-153, 1982.
- Ali, M. Babai, J. Boylan and A. Syntetos, “On the use of Simple Moving Averages for supply chains where information is not shared,” International Federation of Automatic Control, p. 1757, 2015.
- Bordoloi, J. Fitzsimmons and M. Fitzsimmons, Service management: operations, strategy, information technology, (9th ed.)., New York: McGraw-Hill, 2019.
- Dekker, K. v. Donselaar and P. Ouwehand, “How to use aggregation and combined forecasting to improve seasonal demand forecasts,” International Journal of Production Economics, pp. 151-167, 2004.
- Shastri, A. Sharma, V. Mansotra, A. Sharma, A. S. Bhadwal and M. Kumari, “A Study on Exponential Smoothing Method for Forecasting,” International Journal of Computer Sciences and Engineering, pp. 482-485, 2018.
- R. Jacobs and R. B. Chase, Operations and Supply Chain Management, 15th edition, New York: McGraw-Hill Education, 2018.
- G. Schroeder, S. M. Goldstein and M. J. Rungtusanatham, Operations Management in the Supply Chain: Decisions and Cases, 6th edition, New York: McGraw-Hill Higher Education, 2013.
- Pujiati, D. Yuniarti and R. Goejantoro, “Peramalan Dengan Menggunakan Metode Double Exponential Smoothing dari Brown (Studi Kasus: Indeks Harga Konsumen (IHK) Kota Samarinda),” Jurnal Eksponensial, 2016.
- Nurrohmah and E. Kurniati, “Penerapan Metode Double Exponential Smoothing Dari Brown Untuk Peramalan Jumlah Produksi Air,” Jurnal Matematika, 2022.
- Hartini, Teknik Mencapai Produksi Optimal, Bandung, 2011.
- -C. Chang, Y.-W. Wang and C.-H. Liu, “The development of a weighted evolving fuzzy neural network for PCB sales forecasting,” Expert Systems with Applications, pp. 86-96, 2007.
- Talib, Z. Rahman and M. Qureshi, “PARETO ANALYSIS OF TOTAL QUALITY MANAGEMENT FACTORS CRITICAL TO SUCCESS FOR SERVICE INDUSTRIES,” International Journal for Quality Research, pp. 155-168, 2010.
- Cervone, “Managing digital libraries: the view from 30,000 feet, applied digital library project management-using Pareto analysis to determine task importance rankings,” OCLC Systems and Services: International Digital Library Perspectives, pp. 76-81, 2009.
- Karuppusami and R. Gandhinathan, Pareto analysis of critical success factors of total quality management, The TQM Magazine, 2006.
- Brinkmann and S. Kvale, Doing Interviews, Sage Publications Ltd, 2018.
- Knott, A. H. Rao, K. Summers and C. Teeger, Interviews in the social sciences, Nature Reviews Methods Primers, 2022.
- Smit and A. J. Onwuegbuzie, “Observations in Qualitative Inquiry: When What You See Is Not What You See,” International Journal of Qualitative Methods, 2018.
- E. McKechnie, “Observational research,” in The Sage encyclopedia of qualitative research methods, SAGE Publications, Inc, 2008, p. 573.