SPC with the future in mind

It was because of flexibility that Europe’s largest weld nut manufacturer, BAS Components, opted for a PC based SPC system rather than a dedicated one. It meant that the company would not be locked into a proprietorial software and that the PCs, located on the shopfloor could be used for other tasks.

BAS Components Limited, a subsidiary of TT Group plc, is used to working to tight deadlines and exacting requirements: the company is Europe’s largest weld nut manufacturing facility, producing 450 million fasteners per year. Much of the company’s output is destined for the Automotive industry and this requires a close attention to quality which permeates every aspect of the business.

BAS Components uses a cellular manufacturing system, designed and commissioned to meet high speed production, of even small batches and which cuts out wasteful handling costs. The focus is very much on fault prevention and conformance to recognised standards, specifications and customer requirements. BAS conforms to DIN, ISO9001, QS9000 and other automotive specific standards. Inspection controls are stringent including inspection of raw materials, in process operator SPC, first off production inspection, functional and laboratory testing and full batch traceability systems.

Keith John is the quality manager at BAS Components’ Pembroke based factory and he has many years experience in manufacturing and the application of SPC (statistical process control) to practical manufacturing. Keith was aware that the company’s SPC system was not Y2K compliant and set about searching for a new solution which would not only operate into the next century but which met the company’s requirements both in functionality and flexibility.

It was because of flexibility that BAS Components opted for a PC based rather than a dedicated system. It meant that BAS Components would not be locked into a proprietorial software and that the machines, located on the shopfloor could be used for other tasks such as filling in machine downtime sheets. It was at this point that Adept Scientific was approached to supply the SPC software.

The new PCs are located on the shopfloor, where they act as stand alone measuring stations networked into BAS Components’ manufacturing system. Data is either input manually by operators or via digital measuring instruments with RS232 connection. Operators have found it much more comfortable to use the PC screens than the small displays on the previous system. Now the charts are displayed on a full size screen whereas the old system had an electronic calculator-type display. The new method of working provides maximum flexibility for the operators who can gradually gain increasing access to the functions and facilities as knowledge and experience increases. As the operator’s experience grows they can make more decisions in respect of the manufacturing process. “ The PCs are empowering for the operators,” says Keith, “now they can take action much sooner than they were able to with the paper documentation system.”

With Adept’s NWA Quality Monitor software all plant floor workstations use the same core software with task specific configurations for each application. This means that training is reduced and workflow procedures can be standardised and yet each measuring station can be tailored exactly to the requirements of that part of the factory. With real-time SPC feedback throughout the operation BAS Components is better able to reach its target of zero defects.

NWA Quality Analyst is designed to be tailored to customers’ working practices. It has simple direct data file and chart set up and configuration, it is possible to go from start-to-chart in as few as two mouse clicks. Data can be conveniently analysed from multiple perspectives and charting procedures are easily automated by guided Wizards.

As well as default settings for producing charts in the most commonly accepted form, charting procedures can be easily customised to meet internal customer or regulatory requirements. For example, with process capability analysis you can select from more than 20 capability indices, including those conforming to Automotive Industry Action Group guidelines.

The fact that NWA Quality Monitor and NWA Quality Analyst use the same file format also means that if there are any customer queries on the manufacturing data the quality manager can pick up the data file and examine it, sort and filter the data as required to produce a specific chart or report for the customer.

The whole of the manufacturing operation at BAS Components is also monitored using the Quality Supervisor module that allows the foreman to visually check that the process is in control and producing within product specification.
When first installed the software at BAS Components was DOS based and although Keith John says that it was very easy to configure the company has for the last few months been trying the new Windows based versions.

The Windows package is even easier to set up as it follows a logical flow, it has increased flexibility in assigning properties to the various objects the user places on screen. The Windows version makes significant time savings with its chart grouping capabilities - you can display up to four charts on the screen at the same time rather than needing to bring them up one at a time. With four variables displayed at the same time operators are able to visually cross check the results for consistency and problems are spotted earlier. The increased data capture that is now possible gives better process control and a decrease in rejects.

The Windows version has a more flexible screen layout, and the greater available screen area means that all the physical measurements and the attribute data can be entered on a single screen which is much better for operators. A second screen is used to hold a drawing of the component being measured so the operator knows exactly what to measure and the nominal dimensions. Later BAS Components hopes to add a third page that will contain details of quality alerts that arise from time to time. This would be an extremely convenient way of distributing this information to everyone on the shop floor without the need for paper documents. The Windows version supports the inclusion of bit mapped representations of both drawings and photographs of parts for identification and instructions.

BAS Components are using the software with both existing customers and potential customers. For new products or new customers BAS Components can produce meaningful initial sample studies. The feedback on the results and graphs produced for customers has been very positive, particularly as graphs can be formatted to suit customer requirements. When showing potential customers the manufacturing facilities the SPC system is always included on the tour, “It illustrates that we take quality very seriously.” says Keith “A number of our customers have even been to see the SPC system with a view to improving their own facilities.”

“One of the key features of the NWA Quality Analyst and NWA Quality Monitor packages is that they are flexible and fit in with the way you work.” says Keith “You do not need to change your working practices to fit the software.

“ It is essential with any system that you introduce that it does not put extra burden on the people on the shop floor, their role is to manufacture product.”

The introduction of NWA Quality Analyst and NWA Quality Monitor into the manufac-turing process has enabled significant time savings to be made by BAS Components. “Over the three shifts we are saving about £5000 a year and the Windows software is reducing the labour time even further.” says Keith John.

Adept has also been on hand to ease the transition to the new system .”Whenever we have had need to contact them, “says Keith, “if one of our regular contacts can not solve our problem they soon come back to us with someone who could. When we’ve had problems with files we can email these over to Adept and their product specialists are soon able to point out where the errors are and how to put them right. Adept has been excellent in supporting us on every occasion.”

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