1 January 2006
Integration Fuels Plant SMARTS
Make more informed decisions with plant intelligence tools
By Phil Aponte and Greg Richards
Up to now, manufacturers could increase efficiency just by raising levels of automation. Today, the important factor is to use all the data a company gathers and relate it to each other, using it to make decisions to deploy all the company's resources.
Deploy these plant intelligence resources:
The challenge is to make the data available to business intelligence systems without reformatting and transmitting to another database.
Modern SCADA or process visualization systems can help push that data up into the business systems, giving operators a more direct view to the data with no need for manipulation.
The progressive integration of IT solutions at different levels within a company produces a constantly increasing volume of data, which gives users a basis for decisions to help control and optimize company processes. And these user groups such as operators, quality assurance, accounting, logistics, and management all use information in different ways.
Consistent systems that reach from the production or process level (controls) to the MES/ERP system remain rare. It's not a lack of IT-supported processes that prevents consistency because all the most important IT software components are available in principle. The real issue is using them effectively.
People are still critical of investments that have not paid off. So you should assume merely 15% implementation meet criterion to integrate ERP systems in the MES level. Just as important, it's not normal to have optimum linking of production to the MES level. The final result is heterogeneous IT landscapes with lots of data of different quality and quantity to meet the user groups' requirements.
You need time to implement, maintain, and extend solutions like these. And due to lack of consistency, you also need gurus who know a lot about internal relationships within these custom solutions. Data for decision-making usually doesn't come from system data, but rather goes through manual registration. The aim of an efficient, intelligent solution is to initially help those concerned access the same basic data, regardless of their requirements. It should give them a consistent global picture of the company and processes in all views and at all times.
We need intelligent solutions at all three functional levels of a company, such as the enterprise resource planning (ERP), management information system and manufacturing execution system (MIS/MES), and controls levels.
Business intelligence means grouping all the applications, procedures, and processes at the ERP level into an integrated solution that increases efficiency and reduces costs.
Plant intelligence includes efforts in producing companies to intelligently use information within a plant to reduce costs, avoid scrap, improve production facility loading, and in the final analysis, achieve greater effectiveness and economy. Plant intelligence is one way of compensating the lack of consistency in existing applications within the company.
Intelligent solutions are also gaining ground at the automation level. Process intelligence ensures detection and diagnosis of faults in the system or in the process at anytime and anyplace. It allows you to use information to make the right decisions for smooth process sequences and minimize down times to increase availability. While process intelligence has not yet established itself as a concept, in principle, it does describe exactly the facts of the situation.
Today's modern SCADA or process visualization systems provide all the requirements you need to practically implement intelligent solution on a flexible and economic basis. As an interface and with this window on the process, these systems play a significant part in constructing new plants on green-field sites as well as in extending existing production facilities to be open and scaleable. They are platforms for IT and business integration you can enhance at any time.
On one hand, SCADA systems are above the automation level with field units, controllers, and local operator panels; on the other, you can use them for integrating additional functions. Leading-edge process visualization systems also have an integrated process data archive; they're based on Microsoft SQL Server 2000. You can use them for analysis and evaluation as process historians. You can use this process database, which you can also install on a central server, to archive and store process values, messages, and any user data, such as recipes, machine-setting data, and orders, at the performance levels you need in rugged process operations. It's perfectly realistic to acquire 10,000 measured values and 100 messages per second. High-performance profiles, data compression, archiving mechanisms, and redundant solutions are equally important for reliable long-term archiving.
Appropriate openness in most systems gives you space to make individual extensions. Some integration approaches are: ActiveX controls for vertical market and technological extensions, all facets of non-proprietary process communication via OPC to data exchange across different operating system platforms, standard interfaces for external accesses to the database, and programming interfaces and powerful script languages.
How to implement
Two approaches for implementing plant intelligence include the topdown and the bottom-up approach. The top-down approach is preferable in the presence of few to no dependencies on an existing automation landscape or IT infrastructure. Based on the business processes, you can plan the additional processes from the SCADA level down to the automation level. The seamless integration of subordinate components (HMI and PLC) facilitates access to local data and functions. In practice, however, you need to deal with existing system structures. In this case, you may prefer a bottom-up approach with the goal of expanding the existing structures to create a plant intelligence solution that includes all existing components at minimum expense but with maximum benefits. Here's where the SCADA system plays a central role in optimizing the processes.
An ARC Advisory Group forecast said the demand for an increased exchange of information between production and business management applications as well as new requirements of information from the shop floor will lead to a shift from HMI/SCADA technology to higher level functions. The HMI/SCADA suppliers recognizing these trends will become or remain market leaders.
Modern SCADA systems represent an ideal platform for integrating plant intelligence into the production process. An optional central process historian can acquire and archive large volumes of data from different sources at high performance levels. This makes it into the central information exchange or the basis of the plant intelligence solution. Improving and optimizing the process is absolutely conditional on it being possible to generate from process data information you can use on a general basis.
You can display and analyze the information stored in the process database using either built-in functions (from trends to statistical evaluation functions) or special function modules. It is also possible to pass on the information to higher level applications at the MES and ERP level for further processing.
Intelligent tools allow you to calculate parameters, such as equipment effectiveness (OEE) and key performance indicator (KPI), that make possible comparisons. OEE informs of the actual performance in relation to the maximum performance. It is yielded from the relative availability, performance, and quality. KPIs are key indicators the system determines online from the current and historical production data. They give information about the current production status, and they can signal upcoming changes in the process.
People frequently use tools like Microsoft Internet Explorer or Microsoft Excel for displaying information and evaluation. This means you can display and evaluate current process status conditions and historical data on office PCs, including simple visualization of plant pictures and logging of archive data (with no operator input option), as well as current and historical process information by means of appropriate reports in tables and curves. You also have the option of ad hoc filtering and selection and exporting the data.
Web-based standard solutions
In the case of a Web-based solution as offered by the SCADA systems on the market today, the analyses and evaluations are accessible to all the people involved in the process and can occur anywhere in the company. This means of course that cross-site comparisons of production data are also possible. Innovative solutions for machine-level HMI systems have their own integrated Web servers. The system can even represent the screens or process status conditions of local operator stations across the Web on the SCADA system. If the process data archive will also acquire current process data, you can use mechanisms like OPC DA or OPC XML.
If needed, use the Web solutions as an integration platform. Convenient services and tools include the ability to automatically distribute customer-specific objects (controls, files) to the linked Web clients. You also can integrate these into a global navigation system. Then, you can use a Web solution as an information (plant) portal. In conjunction with representing information from any database, you can group this and other information from systems the company uses in the back office or ERP to any views you like. This type of representation and evaluation allows you to quickly evaluate the production situation, which represents a tool for operation and production management.
Plant intelligence doesn't necessarily mean a closed, automated control circuit. The real challenge is monitoring the availability and utilization rate of production on a precise, effective, and consistent basis to help companies make well-grounded decisions. Open and scalable SCADA systems are a cost-effective way to do it.
ABOUT THE AUTHORS
Phil Aponte is a marketing manager for SCADA products at Siemens Energy & Automation in Norcross, Ga. Reach him at email@example.com. Greg Richards is a control engineer at Quadrant Engineering Plastic Products in Redding, Penn.
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