Analysis and proposal of reduction of lead time in the process of cutting, loading and transportation in a sugar cane factory: a study case

Abstract This article parts from the importance of sugarcane based energy to the Brazilian economy and, consequently, the important role of the process that involves cutting/loading/transportation (CLT) of cane in the supplies and production cost of sugar, alcohol and its derivates. For this purpose, a study case was carried in a sugarcane factory from São Paulo state, aiming to build a proposal that could reduce the lead time in the CLT process through the analysis of the Manufacturing Critical-Path Time (MCT) of the studied industry. With the data collected in the field visits, the MCT of one tone of sugarcane during its logistic process was done. This tool revealed a long waiting time of the cane waiting to be milled in the patio of the factory. Through the theory of dynamic of the systems it was concluded that this time was high due to the variability of the field as a consequence of an inefficient use of the harvester and the logistic system of dynamic allocation of the transportation resources ahead in the harvest. To make the harvester more efficient, a reduction of 40% of the laying time “awaiting transshipment” was proposed, which would result in a save of R$ 1.172.784,00/year. For this reduction five proposals were identified to be implemented in parallel: integration of the systems of the board computer and the traffic control system; integration of the board computers of the harvester and the transports; implementation of truck filling volume sensors; focus in the management of basis leaders; and, implementation of a multitask worker.

摘要 本文立足于甘蔗能源对巴西国民经济的重要价值，进而探讨甘蔗切割-装载-运输（cutting/loading/transportation，简称CLT）流程对食糖、乙醇及其衍生品的原料供应与生产成本的关键作用。为此，研究选取圣保罗州的一座甘蔗加工厂作为案例对象，通过分析目标企业的制造关键路径时间（Manufacturing Critical-Path Time，简称MCT），旨在提出可缩短CLT流程前置期的优化方案。结合实地调研采集的数据，本研究核算了单吨甘蔗在物流流程中的制造关键路径时间。该分析工具揭示出，甘蔗在厂区堆场等待碾磨时存在较长的等待时长。基于系统动力学理论，研究得出该等待时长偏高的成因：一方面源于田间作业的波动性，另一方面则是由于收割机使用效率低下，以及收获前期运输资源动态分配的物流调度系统存在缺陷。为提升收割机作业效率，研究提出将"待转运停留时长"缩短40%，预计每年可节省1172784.00巴西雷亚尔。为此，研究明确了五项可并行落地的优化方案：一是调度计算机系统与交通管控系统的集成；二是收割机与运输车辆的车载计算机互联互通；三是部署货车装载量传感器；四是强化基层管理人员的运营管理；五是设置多技能作业岗位。