Penjadwalan Produksi untuk Penjadwalan Flexible Flowshop dengan Menggunakan Metode Longest Process Time (LPT).

Perusahaan Raket PT raket RAB Usaha Kecil Menengah (UKM) yang bergerak di bidang manufaktur, produk utama dari perusahaan raket abadi adalah produk raket bulu tangkis yang nantinya akan di kirim ke beberapa kota di Jawa Timur maupun luar provinsi. PT raket RAB ini mendapat pesanan rata-rata 650 raket tiap bulannya, selain pembuatan raket bulu tangkis, berbagai macam warna dan tipe. Masalah yang dihadapi Perusahaan Raket ini adalah perusahaan belum menggunakan penjadwalan yang tepat sehingga menyelesaian produk yang kurang tepat waktu. Perusahaan menyadari bahwa penyelesaian produk yang tepat waktu ini mempengaruhi kepuasan pelanggan dan dapat meningkatan permintaan produksi.Dengan melihat order bulan maret 2017, terdapat 20% produk mengalami keterlambatan penyelesaian pekerjaan, sehingga perusahaan akan mengalami kerugian dalam biaya pengerjaan. Berdasarkan hal tersebut, CDS akan diterapkan untuk menyusun jadwal yang optimal. Lebih lanjut, akan diterapkan untuk menyusun jadwal mesin produksi pada perusahaan manufaktur. Berdasarkan hasil penjadwalan dengan metode CDS pada perusahaan manufaktur menghasilkan tujuh iterasi. Nilai iterasi ke-1 371,5, ke-2 358,5, ke-3 358,25, ke-4 358,25, ke-5 358,25, ke-6358,5, ke-7 355,5 dengan nilai makespan optimal sebesar 355,5 jam.

An Improved Discrete Artificial Bee Colony Algorithm for Flexible Flowshop Scheduling with Step Deteriorating Jobs and Sequence-Dependent Setup Times

This paper studies a flexible flowshop scheduling problem with step-deteriorating jobs and sequence-dependent setup times (FFSP-SDJ&SDST) where there are multiple unrelated parallel machines at each stage. The actual processing time of each job is modeled as a step function of its starting time. An integer programming model is first formulated with the objective of minimizing the total weighted completion time. Since this problem is NP-complete, it becomes an interesting and challenging topic to develop effective approximation algorithms for solving it. The artificial bee colony (ABC) algorithm has been successfully applied to solve both continuous and combinatorial optimization problems with the advantages of fewer control parameters and ease of implementation. So, an improved discrete artificial bee colony algorithm is proposed. In this algorithm, a dynamic generation mechanism of initial solutions is designed based on job permutation encoding. A genetic algorithm and a modified variable neighborhood search are introduced, respectively, to obtain new solutions for the employed and onlooker bees. A greedy heuristic is proposed to generate the solutions of the scout bees. Finally, to verify the performance of the proposed algorithm, an orthogonal test is performed to optimize the parameter settings. Simulation results on different scale problems demonstrate that the proposed algorithm is more effective compared against several presented algorithms from the existing literatures.

Algoritma LPT-Branch and Bound Pada Penjadwalan Flexible Flowshop untuk Meminimasi Makespan

This article discussed the problem of flow shop scheduling to minimize the makespan. The purpose of this article is to develop the LPT and Branch And Bound (LPT-Branch And Bound) algorithms to minimize the makespan. The proposed method is Longest Processing Time (LPT) and Branch And Bound. Stage settlement is divided into 3 parts. To proved the proposed algorithm, a numerical experiment was conducted by comparing the LPT-LN algorithm. The result of the numerical experiment shows that LPT-Branch And Bound's proposed algorithm is more efficient than the LPT-LN algorithm.