Production Scheduling in Copper Electrorefining and Electrowinning Plants with Manufacturing Execution Systems

摘要

Copper electrolysis process is used to produce pure, over 99.99% copper with the help of electricity. Production dispatching and scheduling in copper electrolysis processes have been done mostly manually and without direct link to automation systems. Disruptions in the production processes usually require new decisions from production planners and changes to production schedules. Manual transfer of information is prone to errors and the transfer process usually takes longer time. In copper electrolysis production scheduling is put into practice by controlling the cranes, which are handling all the material transfers in the plant. One of the objectives of this thesis was to research how to implement new production dispatching features to the existing manufacturing execution system. Theoretical part of this thesis consists of introduction of suitable technologies and standards that could be considered as basis for the empirical research. The foundation for a fully automatic production scheduling and dispatching is a reliable communication between the manufacturing execution system and the automation system. This thesis work contains a review of multiple standards and ready-made commercial products that support these dispatching operations. The empirical part of this thesis consists of design, implementation and testing of a daily production schedule software for cranes. The implementation includes communication and data collection infrastructure but all user interface components are out the scope of this thesis. Also the high level fully automatic scheduling workflow was designed in a high level but was not implemented during this project. This implementation leveraged new products in the field of software technology. Suitability of these products for this and similar projects were evaluated. Most of the problems faced during the implementation were related to a commercial software platform selected for the implementation. Therefore it was suggested that the further use of the commercial product will be put on hold until these problems get fixed by possible software updates. Further development is related to the fully automatic scheduling and also for the development of the user interface.