Girinata, Farras Samudra Alif (2026) Optimization Of The Replenishment System For Coffee Vending Machines Using An Integrated Inventory And Periodic Vehicle Routing Problem With Time Windows (IPVRPTW) Model. Other thesis, Institut Teknologi Sepuluh Nopember.
![[thumbnail of 5010211165-Undergraduate_Thesis.pdf]](http://repository.its.ac.id/style/images/fileicons/text.png) |
Text
5010211165-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (2MB) | Request a copy |
Abstract
The efficiency of replenishment logistics plays a critical role in the profitability and service reliability of automated retail networks such as coffee vending machines. The case study company currently applies a reactive replenishment policy in which machines are serviced only when stock levels become critically low. This practice results in frequent stockouts, inefficient routing, and elevated logistics costs. This thesis proposes and evaluates an optimization framework based on the Integrated Inventory and Periodic Vehicle Routing Problem with Time Windows (IPVRPTW), which jointly determines replenishment quantities, visit frequencies, and delivery routes with the objective of minimizing total logistics cost while maintaining product availability. A hierarchical heuristic approach is implemented. K-Means clustering is first used to group vending machines into geographically coherent service zones. Visit frequencies are then optimized by balancing inventory holding and transportation costs, after which weekly delivery schedules and daily routes are generated using Tabu Search and Cheapest Insertion heuristics. The proposed policy is evaluated through Monte Carlo simulation and compared against the company’s reactive policy and a classical PVRPTW formulation. The results show that the IPVRPTW policy eliminates stockouts while achieving the lowest total logistics cost, reducing transportation effort and fleet utilization compared to current practice. These findings demonstrate that integrating inventory and routing decisions provides measurable operational and economic benefits for vending network replenishment planning.
=================================================================================================================================
Efisiensi logistik pengisian ulang memiliki peran penting terhadap profitabilitas dan keandalan layanan pada jaringan ritel otomatis seperti mesin kopi otomatis. Saat ini perusahaan studi kasus menerapkan kebijakan pengisian ulang secara reaktif, yaitu mesin hanya dikunjungi ketika persediaan sudah sangat rendah. Praktik ini menimbulkan risiko kehabisan stok, rute distribusi yang tidak efisien, serta biaya logistik yang tinggi. Penelitian ini mengusulkan dan mengevaluasi kerangka optimasi berbasis Integrated Inventory and Periodic Vehicle Routing Problem with Time Windows (IPVRPTW), yang secara simultan menentukan jumlah pengisian, frekuensi kunjungan, dan rute distribusi dengan tujuan meminimalkan total biaya logistik sambil menjaga ketersediaan produk. Pendekatan heuristik hierarkis diterapkan dalam penelitian ini. K-Means clustering digunakan untuk membentuk kelompok mesin berdasarkan kedekatan geografis. Selanjutnya frekuensi kunjungan dioptimasi melalui analisis trade-off antara biaya persediaan dan biaya transportasi, kemudian jadwal mingguan dan rute harian dibangun menggunakan metode Tabu Search dan Cheapest Insertion. Kinerja kebijakan IPVRPTW diuji melalui simulasi Monte Carlo dan dibandingkan dengan kebijakan reaktif perusahaan serta model PVRPTW klasik. Hasil penelitian menunjukkan bahwa kebijakan IPVRPTW mampu menghilangkan kejadian stockout sekaligus menghasilkan total biaya logistik terendah, serta menurunkan beban transportasi dan utilisasi armada dibandingkan kondisi eksisting. Dengan demikian, integrasi keputusan persediaan dan perutean terbukti memberikan manfaat operasional dan ekonomi yang signifikan pada perencanaan pengisian ulang jaringan mesin penjual otomatis.
Actions (login required)
 |
View Item |