Connect the plant floor to the supply chain
Plant-floor systems and process automation software suppliers are linking with enterprise systems and the supply chain, and vice versa. Here's help on what to consider and how software can help.
W ithout adequate interconnections with the plant floor, the supply chain's just guessing about where orders are, what inventory is needed, and what the most profitable use of resources should be.
In the most competitive markets, it's no longer company versus company, but supply chain versus supply chain. Enterprise resource planning (ERP) and related systems must interconnect with manufacturing processes to maximize use of resources.
Automation and control software, manufacturing execution systems, plant portal and information systems, and other software aim to provide the interconnectivity and two-way information flow needed.
'The typical model for interfacing plant-floor systems with enterprise and supply-chain systems is direct database access to a production database,' explains Ron Wiles, Lockwood Greene Engineers (Spartanburg, S.C.) Such a database maintains production information required for supply-chain management, machine maintenance, quality control, and management reporting, he says. 'This information is also made available to the enterprise via intranet and Internet applications.'
The diagram, translated from a Microsoft Visio 2000 software, illustrates a typical relationship of plant-floor automation systems with the ERP and supply-chain systems. Lockwood Greene supplied the diagram for use here.
There are three primary interconnectivity schemes, explains Mr. Wiles:
Direct database access
Flat files (using FTP, etc.)
The database is typically a relational database which is SQL compliant (Oracle, SQL Server, DB2, etc) and can be accessed through standard application programming interfaces (APIs).
This model allows easy maintenance of the information available by relying on the relational database's ability to modify tables with minimal impact on related processes. It provides current information to all processes, relieving many of the synchronization issues encountered with interprocess messaging and flat-file transfers.
Keys to integration are interaction of receiving, scheduling, and shipping processes, Mr. Wiles says. All must be tightly integrated with the plant floor systems via the production database.
The scheduling process is the primary interface to the shop floor. It converts customer orders into manufacturing orders (batch, assembly, etc. based upon customer delivery dates, manufacturing capacity, inventory on hand, etc.). The schedule is typically provided to area controllers, which in turn drive Cell Director selection of setup/recipe instructions for the Cell Controllers, Mr. Wile says. The Cell Controllers report status of the manufacturing process to the Area Controller (or directly to the production database).
Scheduling input is also provided to the ERP system so that supplier orders can be placed or materials released for shipment as appropriate.
Raw material receiving and finished goods shipping are import to the plant-floor processes. Typically, Mr. Wiles says, they feed the scheduling algorithms, but the plant floor must have emergency responses to material shortages, storage/buffers for finished goods, etc.
Advice from Mr. Wiles includes:
Production database design-Particular care must be taken to design the information into the production database. Interface specifications then specify the access methods and timing for interaction with the database. Interprocess communications must continue to be considered in the specification.
Access to production database-The number of users (typical, peak, and simultaneous) drives the production database design.
Security-customer/supplier access levels. For example, a trusted just-in-time (JIT) supplier may warrant access to the production data to initiate the required material releases. A user may want to limit customer access to order status at a level above the plant floor cells.
Are production workstations supplied JIT or is inventory maintained at the manufacturing facility? If inventory is maintained, the warehouse management system (WMS) must have the capability to direct/manage material releases to the floor.
Material Releases to production areas: Kanban (visual) request by automated trigger requires devices to initiate the request. Beware of the simple light system-wiring, lights, etc., over a large facility-can be more expensive than a graphical system using the factory network infrastructure. Barcode readers/scanners must be integrated with the work processes.
Quality is another key interface. How is quality captured for feedback to the supplier management processes? How is quality implemented with suppliers-random checks on supplier program, 100% inspection on new suppliers, etc? What quality is required by the specific work areas?
For more on connecting manufacturing to the supply chain, see below and search at Control Engineering Online .
|Web technologies aid CNC integration|
Factory control 'rescues' supply chains, Sun says
Over the last year a funny thing happened to the supply-chain visionaries: they recognized that plans are not actions, they discovered factories, and began talking about a new applications area called supply-chain execution, observes Robert W. Atherton, worldwide manager, Process Control, Sun Microsystems Inc. (Palo Alto, Calif.).
'None of this was news to control engineers, who have long recognized that supply-chains consist of factories and logistics, and that factories contain organized systems of devices and machines,' Mr. Atherton explains. 'To the control engineer, supply-chain execution means we can now do distributed, flexible, hierarchical control and provide some substance the ethereal plans of the supply-chain visionaries.' The functional result, he says, is that factory controls are in a position to 'rescue' supply chains.
Sun Microsystems' Java technology aims for a 'unifying reach from the sensor to the supply chain,' and to 'provide the technology basis for the distributed control structure needed for true supply-chain execution,' Mr. Atherton says. At the recent ISA 2001 show in Houston, Sun and its partners, SoftPLC, Cyberonix, Mitsubishi Electric, GenRad Software, and Auspice, provided a solutions stack that supports true supply-chain execution.
At the top of the stack is the TLX engine from Auspice. TLX, a meta-control system, provides Java-based connectivity linking factory control systems to supply-chain planning engines and enterprise resource systems. GenRad's Java-based SCE application is a flexible and powerful manufacturing execution system, Mr. Atherton says. The Java automation bus (JAB) of Cyberonix and Mitsubishi provides PLC hosting layer and SCADA functionality. The revolutionary SoftPLC provides an industrial controller capable of running ladder logic and can function as Java-based web-server.
'It has been interesting to watch enlightenment come to the supply-chain optimizers,' Mr. Atherton says; fortunately control engineering is ready with Java-based systems to provide the control systems behind true supply-chain execution.'
Microsoft BizTalk Server brokers information transfers
Microsoft Corp. (Redmond, Wa.) has a number of software and framework tools to support and facilitate information exchange, such as the .NET in Manufacturing initiative. Recent announcements on Microsoft BizTalk Server show how related technologies can broker information among the plant floor and other areas of the plant and supply chain.
BizTalk-used by enterprise software vendors, such as SAP, PeopleSoft, Oracle, and J.D.Edwards-can be used to create an XML-based map of information from application to application, doing away with the need to create custom drivers.
Exchange chemical data with Microsoft CIDX Software Development Kit
Exchanging information within chemical industries became a bit easier, Microsoft says, with introduction of its CIDX Software Development Kit this month. The kit-available for free download at www.microsoft.com/bztalk/downloads -uses the chemical industry's core XML protocols developed by the Chemical Industry Data Exchange (CIDX). 'Chem eStandards reduce time, cost, and complexity of making XML-based connections,' says CIDX executive director, Patricia Simmons. The kit augments document schemas shipped with BizTalk Server to include those commonly requested by chemical industry customers, mapping CIDX transactions to SAP intermediate documents. The announcement was made at ISA 2001 in Houston, Sept. 10.
Camstar uses BizTalk in LiveConnect and Virtual Factory Suite
Camstar (Campbell, Calif.) announced LiveConnect, a point-to-framework integration broker based on Microsoft BizTalk Server that creates a hub for collaborative manufacturing and other enterprise applications. LiveConnect is a 'key component,' according to Camstar, in the Virtual Factory Suite of collaborative manufacturing applications. 'Without live information, decision makers have blind spots, which increase the probability of error,' Camstar says, as part of the September announcement.
Ford Motor Co. uses BizTalk Server 2000, XML, SOAP for eHub
Ford Motor Co. (Dearborn, Mich.) has selected Microsoft BizTalk Server 2000, XML, and SOAP (simple object access protocol) for integration architecture and transport protocols for global enterprise application integration and business-to-business integration project, eHub. As of that July announcement, Microsoft said it was the largest BizTalk implementation. The Ford initiative exchanges collaborative information internally and with partners.
GE Fanuc, Datasweep integrate collaborative manufacturing solution
GE Fanuc Automation (Charlottesville, Va.) and Datasweep (San Jose, Calif.) partnered to provide 'world-class supply chain execution solutions,' an integrated, world-class collaborative manufacturing solution globally. Under the Oct. 1 agreement, GE Fanuc can deliver the integrated solution to other GE businesses, the automotive segment, and the process industry
The agreement combines Datasweep's software expertise in web-based manufacturing, repair, and analysis solutions with the e-manufacturing systems, global business reach, and customer support of GE Fanuc, the companies say. GE Fanuc will extend, integrate, and support Datasweep Advantage software under the new name Cimplicity Advantage.
'The global manufacturing community will be able to improve supply chain operations and realize substantial bottom line results from this alliance,' said Kevin Roach, GE Fanuc's vp Cimplicity business. 'The combined manufacturing solution will allow our customers to bring products to their markets faster, raise quality, reduce work-in-process, decrease warranty expenses, and/or generate a higher return on net assets.'
Quality software aims to avoid snarls in supply chain
Quality issues can snarl a supply chain and bring production to a grinding halt, according to Northwest Analytical (Portland, Ore.; NWA Quality Analyst software). Once a supply chain gets interrupted, it becomes extremely difficult to get it back in order. A recent study at Georgia Tech School of Management found that, from 1989 to 1998, supply chain incidents caused company stock values to drop 20 percent over a 180-day period, more than any other external or internal cause.
Companies can mitigate or entirely avoid this nightmare scenario by using web-based SPC software throughout the supply chain.
Northwest Analytical provides the following example:
'Picture an engineer at ABC Electronics at his desk reviewing web-based control charts for Supplier A. The control charts show that Supplier A's process is drifting off target, meaning that Supplier A will be producing very low yields within ABC's specs. In other words, the control charts show that ABC is looking at an impending shortage of material.
'Our ABC engineer checks the ERP inventory for stock on hand: Not enough to get them through a shortage. What about Supplier B? He calls up control charts for Supplier B on the same web-based system. Supplier B's process is right on target as usual. Our engineer calls purchasing and asks them to reduce Supplier A's allocation and double Supplier B's. That avoids a supply chain snarl.'
In essence, Northwest Analytical says, the web-based SPC software is an early warning system that provides the ability to avoid an impending crash in the supply chain.
Northwest Analytical's software includes NWA Quality Analyst, NWA Quality Analyst Web Server, and NWA Quality Monitor.