Factory Integration - Management MIS Systems

INDUSTRY TRENDS

Factory Integration Technologies - (Part 3)

Part 1 of this article introduced some of the integration technologies used at the Control System level of a factory, while Part 2 introduced some of the integration technologies used at the Supervisory Control level. In this, the final part of this series, some of the integration technologies used at the MIS (Management Information Systems) level of an organisation are presented.

MIS Integration

The desire to integrate the MIS level of an organisation with the other levels of its factory management systems is driven by a vision of the globally competitive enterprise with all its critical information available everywhere in an electronic form. The ultimate objective is the ability to make operating decisions and implement them in real time on the basis of accurate, real-time factory information and business conditions.

Systems at the MIS level such as enterprise requirements planning (ERP), manufacturing execution systems (MES) and supply chain management (SCM) promise to increase efficiency, reduce variability and ensure products are delivered on time. However, it all depends on getting in touch with the process and providing the detailed information needed. These systems need specific feedback from the plant for production costing, capacity planning and production scheduling - and the information needs to be accurate and timely.

Therefore, for integration with the MIS level, communication technologies are not the only issues that need to be addressed. In order to move away from complex customised integration solutions at the MIS level, we also need a consistent definition of the functionality that exists in each of the factory floor areas under its control.

SP88

SP88 is an example of a standard that meets this requirement for batch manufacturers in the fine chemical, food and pharmaceutical industries. Started in 1990 by ISA, SP88 was designed to provide consistent definitions, concepts and models for batch control systems. It uses a modular framework and supports plants at varying levels of automation. Its ultimate objective is to allow users to mix and match different vendors' equipment and software.

For example, Dow Corning in the USA developed an SP88-based model to automate batch, semicontinuous and continuous processes. Using the model on a centrifugal compressor system, two operators can now start up the system in 5 minutes, where as it used to take four operators up to 8 hours before.

PC Based Batching Systems

Batching systems provide an "engine" to execute a batching process. They store the batch process (procedures, order of steps, quantities) as a high level recipe and execute the recipe in conjunction with simple control logic at the Control System level. Batching systems record all the actions of the plant and operator. They also interact with higher level systems, such as MRPII and ERP systems to send/receive data. In recent years, a number of PC based batching systems have been released that operate in conjunction with HMI (human machine interface) systems. These types of systems provide very effective integration between the MIS and Supervisory Control layers. Examples of products include Visual Batch by Intellution and InBatch by Wonderware.

Manufacturing Execution Systems (MES)

MES are information systems that reside on the plant floor, between the planning systems in offices and direct industrial controls at the process itself. The functions they provide include:

Manufacturing Process Modelling - production routings, Bills of Material, actual material usage, yields and customer specifications
Materials, Equipment and Labour Tracking - WIP and inventory status, machine status, Time-In-State, machine task scheduling, repairs tracking
Statistical Quality Management - Statistical process control, SPC charts and alarming, associated test result records
Engineering Document Management - Electronic retrieval and presentation of documents
Report Generation - Traceability, yield by operation, equipment downtime and usage, production by machine, route and operator

MES needs to be customised or configured to suit the specific application or site.

Examples of systems available include InfoLink by Realtime Systems and InTrack by Wonderware.

Enterprise Resource Planning (ERP) Integration

Most ERP systems provide interfaces to allow their system to communicate with factory floor processes. For example, SAP R/3 defines an interface called PI-PCS. This provides a solution for process manufacturers to unite SAP R/3 business software with real-time process control. It is a standard, open interface enabling direct integration of the SAP R/3 PP-PI system (Production Planning - Process Industries) with SCADA, HMI and DCS systems at the Supervisory Control level. PP-PI provides a comprehensive suite of process planning tools to manage resources, recipe and process management, as well as process planning and production information management. The SCADA, HMI or DCS systems manage the production process itself and transfer real-time process data back to SAP PP-PI. Therefore, both planned and actual process data is made available to SAP for further processing.

Products that comply with the PI-PCS interface include Visual Flow by EnvisionIt, Enterprise Link by Hewlett Packard, PI System by OSI Software and I/A by Foxboro.

Other products are available for ERP integration, one being Transaction Processor by ISE Inc. It provides integration services for BPCS and PRISM systems and manages communication between MRP systems and MES databases. It monitors plant floor activities and issues transactions to the ERP systems, such as amount of product consumed, product produced and material wasted.

Application Integration

Integration at the MIS level often involves services provided by the computer environment in which the MIS software systems operate. Object-based software technologies to which many of these software systems are migrating provide standard interfaces between different applications and provide fewer integration problems.

Standards at this level include the Object Management Group (OMG) consortium's Common Object Request Broker Architecture (CORBA); Microsoft's Common Object Model (COM) and distributed COM (DCOM), the foundation for its ActiveX and Visual Basic for Applications (VBA) programming tools; or Sun Microsystems' Java. Object-based software promises standards for the interfaces among software modules that will let users easily integrate different packages without custom drivers or code.

Other products, such as Visual Flow by EnvisionIt Software also use software "objects" to provide mechanisms for interfacing between a wide range of non-object based applications.

For example, they can be used to link any of the following with one or more of each other:

Process Control and HMI Systems, such as Fix and InTouch
Business applications such as MRP, ERP and Logistics
Laboratory Information Management Systems (LIMS)
Batch Control Systems
Relational Database Management Systems such as Oracle

Conclusion

Due to the wide range of applications and systems that reside at the MIS level of an organisation, there are a wide range of interface issues that need to be addressed. This article has attempted to introduce some of the technologies available that are making this level of integration more manageable.

In addition to technical issues, organisational issues also play a major role when integrating the MIS level with the Supervisory and Control System levels. Control system engineers and IT (Information Technology) professionals need to work together to implement these systems because they generally don't have detailed knowledge of each other's domain. This can lead to difficulties and misunderstanding - in some cases important technical requirements may "fall between the cracks" at this gap in the hierarchy. While the tools to achieve integration at the MIS level are constantly developing, management and coordination of the team undertaking this work is also a significant issue that will effect the success of the completed system.

Part 1 of this article introduces some of the integration technologies used at the Control System level of a factory. Part 2 introduces some of the integration technologies used at the Supervisory Control level of an organisation.