基于炼钢MES系统的Cpk计算模型建立及应用

Establishment and application of Cpk calculation model based on steelmaking MES system

Cpk是制程能力指数,是制程水准的量化反应。个别重点客户订货时要求某些指标的Cpk值达到国际标准指定的值。为了计算Cpk值,钢厂一般设定特定岗位进行Cpk计算。这些岗位利用Cpk计算方软件,将MES系统中的数据导出,按照Cpk计算软件要求导入,进行Cpk计算。由于操作烦琐,每月抽出一周时间对比较关键的指标进行Cpk计算。计算结束后,将计算结果导出Excel文件通过邮件传递至相关部门。济源一炼钢MES系统上线一年来,各项基础数据逐渐趋于稳定。为了快速根据基础数据了解炼钢过程各重要指标的制程,有目的地对各项指标的制程能力进行改善,特进行Cpk项目的开发和实施。文章以济源一炼钢及一轧钢为例论述钢铁厂Cpk计算模型意义及算法。Cpk项目的实施,不仅提高了Cpk计算效率(对比人工手动计算,计算效率提高2 000多倍),而且通过生产过程各项指标Cpk值,快速掌握生产情况,对出现异常的生产环节,有效进行改进,改善了生产质量,提高了经济效益。

Cpk is the process capability index and the quantitative response of the process level. Some key customers require that the Cpk value of some indicators reach the value specified in international standards when ordering. In order to calculate Cpk value, steel plants generally set specific posts for Cpk calculation. These posts use the Cpk calculation software to export the data in the MES system, import it according to the requirements of the Cpk calculation software,and calculate the Cpk. Due to the tedious operation, one week is set aside every month to calculate Cpk for key indicators. After the calculation, the calculation results will be exported to Excel file and sent to relevant departments by mail. Since the MES system of Jiyuan No. 1 Steelmaking Co., Ltd. was launched one year ago, all basic data have gradually become stable. In order to quickly understand the process of each important indicator in the steelmaking process from the basic data, and purposefully improve the process capability of each indicator, the Cpk project is specially developed and implemented. This paper discusses the significance and algorithm of Cpk calculation model in the iron and steel plant, taking Jiyuan No. 1 Steelmaking and No. 1 Steel Rolling as examples. Through the implementation of Cpk project, not only the calculation efficiency of Cpk is improved(compared with manual calculation, the calculation efficiency is more than 2 000 times higher), but also the production situation is quickly mastered through the Cpk value of various indicators in the production process. The abnormal production links are effectively improved, the production quality is improved, and the economic benefits are improved.