Initial Assessment of Manufacturing Execution Systems : Development of a methodology to define business needs and functional requirements

Abstract: A key component of the smart factories that industry 4.0 introduce is the MES (manufacturing execution system). The MES lies above the actual shop floor in the enterprise system hierarchy and is not in direct contact with the actual production, in the way PLC (programmable logic control) or SCADA (supervisory control and data acquisition) systems are. MES guide, initiate, respond to and reports on the production activities as well as distribute information to other company IT systems, bridging the gap between the control systems of the shop floor and the information systems on an enterprise level. MES is a class of information systems built to support shop floor processes and improve the integration to other departments of the enterprise by incorporating these systems into the overall IT-architecture. The main goal of an MES is to improve and optimize the production management functions and increase visibility into the manufacturing process. The role of the MES is defined by industry standards that identify what functionalities and dataflows an MES should include, and how it is intended to be integrated with other information systems. However, little research has been focused on adopting these standards in actual MES implementation projects. The MESA (manufacturing executions system association) is presenting a standardized definition of MES as well as 2 models of the, according to the standard, 11 key MES functionalities. The ISA-95 (IEC/ISO 62264) standard identifies sub-systems of an MES and defines the boundaries between the ERP, MES and other automation and IT systems. Company parameters such as manufacturing environment, production model and plant type all affect the business needs and what MES functionalities are of priority. Hence, for an MES implementation project, a business-specific evaluation must be performed.  Prior research in the area is presenting a high-level workflow and best-practices of an MES implementation project. By combining this workflow with the general software implementation standard ISO/IEC 12588 (ISO/IEC 15288: System engineering – System lifecycle process), a methodology for performing the initial assessment of a company’s MES needs and business requirements is built. In the methodology models from MESA and ISA-95 are applied to ensure an industry-accepted terminology and process. The objective of the methodology is to provide a standardized way to make an initial assessment of a company’s MES needs and specify system requirements. The methodology is validated through a study performed at discrete manufacturing line. The overall needs and specific functional requirements are identified through the methodology and are presented according to a URS (user requirements specification) for an MES. The requirements are prioritizing according to MoSCoW analysis. Additional validation of the methodology must be performed to further evaluate the suitability of using the methodology for initial assessments of businesses’ MES needs.