# Dye Schedule Optimization: A Case Study in a Textile Industry
###### Abstract  
In a demanding and globalized market, production management plays a fundamental role in the company's reference. Proper management of the production area allows companies to obtain productivity gains, reducing operational costs and make contributions to face the competitiveness of their competitors. When defining its strategic objectives in a productive system, it is necessary to formulate plans to manage human resources and strategies based on requirements. In this context, planning, production, and control (PPC) is an excellent ally of the organizations. The adequate development of the activities of the PPC allows companies to minimize production orders not attended, minimize stocks of raw materials, and finished products, minimize idieness of human resources by efficient allocation of work and minimize production processing times. The present work proposes a study to organize and develop a model that guides the prediction of the setup gain in the fabric dyeing process, structured by the traveling salesman problem.  
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clothing, and retail. Among the different types of fabrics produced, the study turns its attention to the production of denim, a kind of fabric that is the basis to produce jeans.  
Nowadays, most textile industries use automated equipment for scale and quality. In the context of the fourth industrial revolution, the textile industry seeks to expand from automation to planning and scheduling tasks [5]. Until the mid-1960s, many papers published assumed that setup time (cost) was not necessary. However, this assumption simplifies the analysis and compromises the solution quality of many scheduling applications requiring appropriate treatment of setup time (cost) [6].  
Setup times are significant in the textile industry and should be considered as separated. Fabrics are produced on looms with specific adjustments, and when this fabric is changed, the loom must be adjusted accordingly, consuming time that is a scarce resource [7].  
Given the context presented, the following research question arises:  
* How to improve the scheduling of the fabric dyeing process by optimizing setup times?  
This research is positioned in the operational research (OR) in mathematical programming involving integer programming models. It aims to present a solution model for the production scheduling problem applied in a confirmed case of fabric dyeing scheduling, structured in the traveling salesman problem, to optimize the setup. The purpose of this research goes beyond the comparison between scheduling methodology, and it aims to obtain a formulation that can be replicated in companies of the same segment.  
The remainder of the paper is structured as follows. Section 2 presents a literature review with the main concepts, definitions, and approaches on the Brazilian textile sector, planning production control and operational research. Moreover, Section 3 focuses on research methodology, with its characterization and structuring choose the representative features for simulation and comparison between the optimized model and empiric model. Besides, Section 4 shows the evaluation model's structuring, containing the relationship of the result with the parameters. Finally, Section 5 concludes with results and discussions of this application, followed by a conclusion.