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During the past decade, many different PC-based automation software products have been introduced on the factory floor, all promising production benefits and cost savings. Too often, these products were incapable of interfacing with other industrial automation systems. Failing to use standard protocols for communication and lacking the technology for native connections to the structured query language database used to warehouse other company data, these software systems became islands of information. Because they couldn't disseminate information throughout the enterprise and left the isolated data at risk, they lost much of their purported benefit and savings.
To prevent these isolated pockets of data, many organizations now use factory-floor automation systems that provide native links to the SQL database used for front office administrative systems. All mission-critical data collected at the factory-floor level is thus warehoused in one secure place within the enterprise. Along with this trend have come two requirements: Statistical process control data must be provided in real-time to the enterprise database, and SPC software must be capable of using specification data derived from other applications stored on the enterprise server.
To function as part of an enterprise information system, SPC software must do far more than produce colorful charts and graphs. It must meet the technological hurdles of client/server architecture, SQL compatibility, interoperability with other automation systems and exchange data using communication standards such as OLE automation and OLE for process control (OPC). By addressing these technological questions first, a company can select an SPC software system that will ensure enterprisewide system viability without sacrificing statistical performance.
For SPC software to function as a viable part of an enterprise system, selection criteria must include information system issues as well as production and process automation management. Selection teams for SPC systems should include representatives from gaging departments, process engineering, quality management, information services and technology, and senior management.
Advantages of enterprisewide SPC
Implementing an enterprisewide SPC system will significantly reduce overall cost of ownership compared to stand-alone or departmental-based software. Storing all SPC data in an SQL database on the enterprise midrange server eliminates the need to install a separate SPC server requiring separate database maintenance. This not only represents a reduced administrative overhead but also saves the high cost of data recovery operations and the even higher cost of lost data.
An organization operating multiple locations on a single server also benefits from an economy of scale. In addition to the deeper discount obtained for a larger system, an enterprisewide system should offer automatic concurrent licensing and usage metering. With these, the organization only needs to purchase licenses for the maximum number of stations that could be performing operations simultaneously, rather than for every station no matter how infrequently collection operations may occur there.
In addition, by linking to the enterprise database, an SPC system eliminates much redundant data entry and resulting data errors. Using OLE automation or OPC, the SPC system automatically creates part or process specifications from design models stored in other applications. And by interfacing with production scheduling applications, the system can load collection plans automatically and begin monitoring automated processes.
These same communication protocols allow the system to communicate with external hardware, providing intelligent feedback to close the loop on the process. This can be used to automatically initiate standard corrective action procedures from models defined enterprisewide.
Enterprisewide SPC also gives real-time access to data where and when it's needed. Production information is available to the enterprise system immediately after any production run is completed. Thus, a predefined batch print configured to report automatically on last month's production can be printed by management the moment the month ends. The shipping department has instant access to predefined customer compliance reports when a specific work order or lot is completed. And lab analysis can be run on production data just minutes old.
Because an enterprisewide SPC system serves a multitude of masters, its functional requirements depend on the responsibilities of the person using the SPC data. However, a number of key characteristics should be present for such a system to operate successfully. For ease of reference, the following requirements have been grouped into three general categories: information systems, quality management and production.
Information system requirements
At the outset of the evaluation process, information system requirements should be considered. If management or production prerogatives are addressed first, purchasers risk selecting software that later will be rejected because of system incompatibility issues. Requirements include:
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Enterprisewide SPC at Work
M&S Manufacturing Co. of Hudson, Michigan, has developed a corporate culture devoted to quality and teamwork. This has included a move from plantwide to enterprisewide statistical process control, according to Information Services Manager Dan Norton. M&S produces automotive parts and components for original equipment manufacturers as well as tier one and tier two suppliers. The company has more than 12 years' experience with SPC and is QS-9000-certified.
"We needed enterprisewide SPC to maintain consistent part quality across the company and to meet customer requirements," explains Norton. "SPC is required by our automotive suppliers, and the related quality reports and charts must accompany all parts shipments."
Because many of the parts or components M&S manufactures move through multiple facilities, with each facility responsible for individual process elements and related data collection, M&S required an enterprise SPC solution to centralize control of specification models while distributing data-collection capabilities throughout all its facilities.
To meet this need, M&S installed WinSPC¨ C/S Enterprise to access the Microsoft SQL database on the company's central server and collect real-time data from client stations at the individual plants. Because the SPC software uses native drivers to read and write all data directly to the central enterprise database, it eased the planned integration with M&S's new MRP application from Monitor Systems.
Enterprisewide access to SPC analysis offers several advantages. "Personnel at all levels, from machine operators to senior managers, can now review the data through reports tailored to their needs," observes Norton. "The system has all the proper reporting, filtering and security." M&S uses the collected data to create custom production and capability reports for specific customers to enhance supplier/vendor quality assurance reporting.
Even though the SPC system includes advanced functions to operate enterprisewide, Norton appreciates that it's still easy for the operator to learn. "It's user-friendly, and the charts and screens are easy to read," he says. |
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 Client/server architecture with native drivers that allow the enterprise SQL database to connect to and use the SPC database without administrative intervention.
Connectivity to any supported PC, midrange or mainframe version of an SQL platform, whether running UNIX, MVS, VMS, VM or NT.
As close to zero-administration functionality as possible. Installation, configuration and upgrades should occur at a single station, and all client stations should be able to self-synchronize.
The ability for clients to run off-line (i.e., store data locally) in the event of database or network failure, as well as automatically upload and resynchronize upon reconnection.
The ability to recover individual clients successfully from the server in the event of client failure or loss.
Built-in concurrent license and usage metering.
Adherence to interapplication communication standards, including OLE automation, OPC and DDE.
Quality management requirements
Quality management, statisticians and corporate-level requirements for an enterprisewide SPC system focus on analyzing collected data to make discretionary decisions impacting future production and revenue levels. Requirements include:
Real-time enterprisewide viewing of all operations with supervisory notification and alarming.
Seamless availability of production data for advanced statistical quality analysis tools.
Batch report capability by week, month, etc., including sorting by user-selected parameters such as operator, department and customer.
Built-in audit trail for applicable compliance reporting, whether ISO 9000, QS-9000 or FDA, and tracking of all data editing and specification changes.
Dynamic building of part and/or process specifications from information entered into complementary enterprise applications. These include enterprise resource planning, manufacturing execution systems, materials requirements planning, and supervisory control and data-acquisition systems.
Unlimited tags during data collection for vendor tracking and component traceability.
Operator viewing of multiple parts and/or processes on-screen simultaneously during data collection.
Production requirements
The production department must focus on controlling the process's physical elements in order to eliminate nonconforming product. Production requirements include:
Factory-floor viewing of enterprise production documents during data collection.
Closed-loop control or statistical feedback that provides standardized corrective action directly to the process, even without operator assistance.
Real-time data collection from multiple parts and/or processes into a single station to reduce the number of collection stations needed.
Direct interface to gages and equipment, including coordinate measuring machines and computer numerical control machines, without additional black box interfaces.
Industry-standard control tests as well as user-defined tests for specific processes.
Flexibility to vary collection method by part, process or both, and continuous process capability viewing in real-time.
An easily learned and used operator interface.
After finding an SPC system that addresses these enterprise requirements, it's important to confirm system operation by installing and running a pilot. To get a true feeling for the software's operation, the pilot should encompass various uses in several departments, including production management and quality personnel.
The pilot also will enable the selection team to assess the vendor's support services. Make certain the vendor offers adequate training, readily answers questions and is responsive to your suggestions. Inquire about future plans for developing the system -- not only to check whether the vendor is keeping abreast of technology to ease future implementation but to ensure that it will be able to address your company's plans for future systems, communications, intranet and Internet development, and so forth. Reviewing the vendor's financials is recommended as well.
It is evident that the focus for choosing an enterprisewide SPC system cannot be solely on charts and graphs -- elements found in every SPC system. Rather, system requirements must center on the technology needed to harness the company's legacy database and interoperate with the enterprise information system. Although selecting enterprisewide SPC involves more individuals in the process and requires a larger initial price tag, it offers a quicker return on investment from reduced overall cost of ownership as well as universal access to real-time production information.
About the author
Ned W. Greenberg is vice president of DataNet Quality Systems, a division of Detroit Gauge Group, precision tooling, gaging, testing equipment and electronic probe manufacturers in operation since 1941. DQS is the developer of WinSPC C/S Enterprise software.
For more information, contact DQS by fax at (248) 357-4933 or by e-mail at ngreenberg@qualitydigest.com | 
