Assembly line balancing is one of the most important management decisions for reducing production costs. So far, many researches have been done in this area. In this research, we expand the U-type line-balancing using goal programming for multi objective model with two goals, i.e., minimized the number of temporary workers and number of cycle time in each station. Additionally, an example to illustrate the model, as well as some analyses is presented. Different amount of time for temporary worker to accomplish their tasks were generated. For some cases, the U-type assembly line is more efficient than the straight one. However, the goal 1 and goal 2 are conflicted

Optimization models are increasingly developed for planning and scheduling in manufacturing of natural resources. However, the uncertainty of material from natural resources makes it more difficult to develop a model. In this paper, we concern about the cost of dry timber preparation for finishing process in a wood-board manufacturer. Based on characteristics of the material and wood-board production process, we develop two models to minimize transportation and drying cost of wood supply. The models consider the capacity of facilities, distances among facilities, and timber specification-based drying periods. The model is solved using linear programming, result in drying allocation of kiln dry’s chambers that gives the minimum cost of the process. A sensitivity analysis is conducted to demonstrate the effect of variation of internal capacity and external capacity to the objective function value. The results show that the total cost is more sensitive to the variation of the external capacity of kiln dry than the variation of the internal capacity.

Penelitian ini dilakukan untuk mengetahui pengaruh dari variabel gaya kepemimpinan transformasional dan gaya kepemimpinan transaksional terhadap motivasi kerja karyawan di perusahaan konstruksi kota Ambon. Sampel yang digunakan adalah karyawan dari perusahaan yang terdaftar sebagai anggota ASPEKINDO kota Ambon tahun 2022. Teknik analisis data yang digunakan adalah analisis deskriptif dan multivariat dengan PLS-SEM. Hasil penelitian pada perusahan konstruksi di kota Ambon, gaya kepemimpinan transformasional berpengaruh positif dan signifikan terhadap motivasi kerja karyawan. Sedangkan gaya kepemimpinan transaksional berpengaruh negatif dan signifikan terhadap motivasi kerja karyawan. Pada gaya kepemimpinan transformasional, ketika semakin tinggi persepsi terhadap gaya kepemimpinan atasan maka semakin tinggi motivasi kerja dari karyawan. Sedangkan untuk gaya kepemimpinan transaksional, mendapatkan kesimpulan berbeda yaitu ketika semakin tinggi persepsi gaya kepemimpinan transaksional maka semakin rendah motivasi kerja dari karyawan.

This article discusses the combination of genetic algorithm (GA) and Data Envelopment Analysis (DEA) to solve the flowshop scheduling problems with multicriteria. The criteria are makespan, total weighted tardiness, and mean flow time. DEA is used to calculate the overall value of criteria from each sequence. Relative efficiency value is employed as the fitted value in genetic algorithm, in order to have overall value that independent to a particular weight. The proposed algorithm that combines GA and DEA attain optimal solutions with relative efficiency as good as analytical solution, i.e., Mixed Integer Programming (MIP). From 30 problems generated, only one problem (3,33%) has relative efficienly less than 1. Abstract in Bahasa Indonesia: Artikel ini membahas kombinasi algoritma genetik dengan Data Envelopment Analysis (DEA) untuk pemecahan masalah penjadwalan flowshop multikriteria. Kriteria-kriteria yang digunakan, yaitu makespan, total weighted tardiness, dan mean flow time. DEA digunakan untuk menghitung nilai keseluruhan kriteria dari setiap sequence dengan menggunakan nilai efisiensi relatif sebagai fitted value dalam algoritma genetik. Hal ini ditujukan agar nilai keseluruhan dari kriteria-kriteria yang ada tidak terikat pada satu jenis bobot saja. Kombinasi dua metode ini menghasilkan suatu algoritma yang mampu menghasilkan kumpulan solusi optimal dengan nilai efisiensi relatif yang tidak kalah jika dibandingkan dengan hasil dari model Mixed Integer Programming (MIP), dimana dari 30 masalah yang dibangkitkan, hanya ada 1 masalah (3,33%) yang memiliki efisiensi relatif di bawah 1. Kata kunci: penjadwalan flowshop, algoritma genetik, Data Envelopment Analysis.

Inventory models for stock-dependent demand have been developed continuously in recent years. In this paper, we develop inventory dependent model for multi-items by considering stock-dependent demand and stock-dependent holding rate for a rack that has a specific capacity. Two models are developed. The first model is an individual order quantity for each item and the second model is a joint replenishment model. The non-linear model with constraint is solved using an evolutionary algorithm. A numerical example and sensitivity analysis are conducted to show how the models work and to get some management insights. The sensitivity analysis shows that there is no dominant model. However, the joint replenishment order outperforms the individual order when the rack capacity is tight and there is a high ordering cost