All the World’s a Batch

Twenty or so years ago, a group of manufacturing and control system engineers from the food, consumer products and pharmaceuticals industries and some of the vendors who predominantly served those industries, got together to talk about a kind of control strategy that was neither fish nor fowl. Continuous processes were well known and the DCS control system was being implemented widely. On the factory floor, PLCs were revolutionizing how discrete processes and motion control were implemented. But nobody seemed to know what do about batch.

These batch pioneers first set out to write a standard for batch control. This standard, now known as S88, is arguably the most successful ISA standard, and the first that successfully crossed over the divide between control systems and automation and the business processes that drive the enterprise.

What the SP88 committee did was to define how a batch process works, and show how to describe it in a clear and repeatable fashion. It differentiated between the equipment and the recipe. It defined how recipes were to be created and how a batch process fit into a set of batch processes.

As soon as the industry realized what a great thing S88 was, the scope of the work shifted and a new committee was formed, to try to define a complete language for describing manufacturing—not just batch, all of manufacturing. This became S95, which has also jumped the chasm successfully and become a highly respected enterprise standard touted by people like SAP and Microsoft, as well as the end users and vendors in the automation marketplace.

Meanwhile, the original group of standards revolutionaries had realized that a language was needed to connect S88-enabled processes to the rest of the plant enterprise, and they developed B2MML, an XML (extensible markup language) variant that allows the batch to speak to the enterprise.

A complete convergence is underway to merge the two standards, S88 and S95 into a complete language and methodology for defining manufacturing operations.

So, in the future, it will be possible to easily and repeatably define and discuss any and all manufacturing operations, thanks to ISA88, ISA95, the B2MML committee and WBF.

But how do we make sure the “languages” don’t split into vendor-sponsored “dialects?” How do we make sure that everybody’s ISA88 implementations talk to everybody else’s? Otherwise, the future of batch will be just as chaotic and fragmented as it was in the early 1980s.

One of the ways is through the new compliance institute that WBF and the Automation Federation have set up under the Automation Standards Compliance Institute. Called the Industrial Interoperability Compliance Institute, its mission is to make sure that manufacturing standards like ISA88 and ISA95 and B2MML are and continue to be interoperable.

What will batch processing be like in twenty years? The work of WBF and ISA88, ISA95, the B2MML committee and others is being supplemented by people who are working to make batch process control smarter, not just interoperable. In the bad old days, which still exist today in many plants, you started out by throwing the ingredients into the pot, applying heat or cold, stirring and hoping that everything would come out the way the “Golden Batch” did in the lab. If the current advanced research pans out, it will be possible to expertly steer a batch to completion and produce easily repeatable batches that meet quality requirements, every time.

In fact, it has been noted that continuous processing shares a great deal with batch, and the principles and practices of S88 can be used there, by envisioning continuous processing as a very long batch, with start-up and shutdown as the start/stop of the batch process.

The future of batch processing is bright—and the revolution in batch process control has only just begun.