Wedgwood aims for china that’s fit for the Queen

Wedgwood designs and manufactures high quality bone china. The site in Stoke-on-Trent employs around 1000 people, and has capacity to produce around 750,000 units per week. Quality of the finished product is of vital importance to the company (and its customers). Although the site originally relied heavily on skilled craftsmanship, it is now reliant on automated technology, with robots, SCADA (supervisory control and data acquisition) systems and automatic guided vehicles now commonplace on the factory floor. The manufacturing process itself is a very complex one, involving many different stages and high value machinery. Ian Ferguson, manufacturing systems improvement manager for Wedgwood, explains some of the problems Wedgwood had to overcome. “The nature and variety of the raw materials involved in the pottery industry…are so diverse that many manufacturers do not even attempt to control them.” There are many different variables affecting the overall quality of the bone china products, and imperfections that could have originated at any stage of the manufacturing process may often only appear in the finished batch of ware. As Ferguson elaborates, “if a batch takes a couple of days to complete and only then is a problem discovered, not only might that whole batch be wasted but potentially all work-in-progress will be suspect.” So why did Wedgwood turn to Automsoft for help? Firstly, it had to be able to trace each and every event that happens to a batch throughout the complete manufacturing cycle. This would then help to establish the parameters that define the “golden batch” for every possible permutation of raw materials. Secondly, this information could then be fed back into the manufacturing machinery with the results consistently monitored against the “golden batch” to ensure ongoing accuracy. In addition, any unexpected problems could be dealt with immediately. With assistance from Keele University, Wedgwood produced a user requirements document, and Automsoft’s RAPID software came out top of the shortlist contenders. Ferguson explains why. “We wanted the latest software architecture combined with an upgrade path involving minimum risk. We felt that RAPID was the best plant information management product that could easily link in with our Mitsubishi MX2000 SCADA package.” Wedgwood chose to use one of their development dust presses as a pilot implementation for the new software – then roll it out to all production machines on the site within the next 3-5 years. In total, the Stoke-on-Trent site will have to spend around £100,000 rolling out the RAPID software to all major machinery around the factory, including hardware upgrades and technical support. The company expects to spend much more over the longer term – “about £1.6 million” according to Ferguson. Even in its first phase, the project is already showing signs of success. Problems surrounding one of the key manufacturing processes – formation of the ceramic plate - are being identified and resolved much sooner than was previously the case. The dust press is used to produce a consistent flatware product. This is achieved by squeezing bone china particles against a membrane under hydraulic pressure using a metal punch. As each part leaves the press, the edge is finished automatically. Inconsistencies at this stage of the process can cause significant quality failings further downstream. Incorrect pressure, incorrect time within the press, below standard materials, and even wrong moisture content can lead to a product that is not 100% accurate. So how has the RAPID implementation improved the plate formation process at Wedgwood? Every stage of the manufacturing process is now logged: humidity of the clay in each hopper is measured; in the plate pressing process, pressure and duration of pressure are both monitored and logged by the Mitsubishi MX2000 SCADA system before streaming into RAPID in real-time. Wedgwood has now reached the stage where it has enough data stored within RAPID to begin identifying the optimum combination of variables to produce the “golden batch”. This data can then be fed back to the actual machinery, where stringent controls can be set to ensure consistent high quality products. The RAPID software will be rolled out to all plant machinery over the next couple of years, with all levels, from boardroom to machine operators, using the software. Ferguson insists that the pilot implementation was relatively problem-free. “There were some minor problems with the RAPID software, but these were overcome easily. However, when we switch the software from the development dust press to the actual production machines, there will be more pressure to get it right. I won’t be quite so keen to halt production if there is a software glitch.” The future looks very bright at Wedgwood – the site is well on its way to achieving its goal of producing “golden batch” product all the time, and Ferguson expects to achieve a return on investment within one year.