Make2Pack helps ISA-88 branch out
Make2Pack is handing off its work to the ISA-88 (S88) committee, creating the new Part 5 portion of the standard with consistent models for manufacturing and packaging software. Potential savings are 50% or more in design, construction, and start-up costs, say those involved. Standards efforts pay off, with potential to revolutionize all of automation, adds David A. Chappell, chairman Make2Pack. Chappell, of Procter & Gamble, is working on Make2Pack and related software and hardware demonstration, along with major end-users (such as Arla Foods, Coors, Dow, DuPont, Pfizer, SAB) and automation vendors (Elau, Mettler Toledo, Rockwell Automation, Siemens, Wonderware), and others.
Beyond the scope of ISA-88 Part 5 (Modular Concepts for Automated Control Systems), Make2Pack members also plan to recommend revisions to clarify assumptions and vagueness in the definitions portion (Part 1) and make the tone less batch-oriented, offering those using the standard more adaptability, including for packaging machines. Not all favor revisiting Part 1 for fear the standard will be less appropriate for its intended batch origins. But the goal, says Dennis Brandl, SP88 chairperson, is to make the standard more beneficial to all areas of automation, without decreasing usefulness for batch. Make2Pack also will feed the new Part 6, addressing the recipe phase to equipment interface. (Work continues to make ISA 88 Part 5 an ISA standard with a vote by early 2007, then fast-track it as an IEC standard.)
Reasons expressed for the changes and additions underway are that automation requirements are similar across manufacturing; end-users have strong desire for improvements; and some OEMs continue to resist change. OEMs are on notice, however; a March 5 letter from major end-users says, in part: “We will evaluate our suppliers’ abilities to deliver such systems based on the draft standard and may give preferences to suppliers who do so.” Modular design saves time and effort because modules can be copied, reused, easily modified, or replaced. That includes defining and separating elements of procedure control and basic control.
“All control related sections of the Part 1 standard assume that the process cell in question (physical equipment and related control activities) has been subdivided into well-defined equipment entities such as units, equipment modules, and control modules,” Chappell says. Such subdivisions are complex, “highly dependent on the individual requirements of the specific environment in which the batch process exists. Inconsistent or inappropriate equipment subdivisions can compromise the effectiveness of the modular approach to recipes suggested by this standard,” he adds. Process cell subdivision requires a clear understanding of the purpose of the process cell’s equipment, allowing identification of equipment entities that must work together to serve an identifiable processing purpose. Part 5 is expected to reduce complexities that exist in creating modular designs and will reduce the need for certain highly specialized skills to design and maintain a modular system.
Make2Pack aims for consistency by identifying four types of control components (CC, which are software objects or groups of code). CCs work within control modules, equipment modules, and units. Persistent control is most basic saying, “do it.” Equipment control is procedural logic that defines “how to do it.” Procedural recipes contain the instruc-tions of “what to do.” Coordination control offers arbitration, at local and unit levels and beyond.
Consistency in software structure and software designs expedites troubleshooting, operations, changeovers, and upgrades, Chappell says. Will it lead to interoperable objects of code that could transfer among manufacturers? Discussions have extended to creating a “WBFDigitalDevice” to preserve information through the product lifecycle stages: define, design, and develop.
The trend extends beyond Make2Pack and ISA-88. Similar “bigger picture” efforts also are under way with OMAC for machine tools and ISA-95 for higher-level data models and structures across manufacturing. Why? “Current methods of delivering new manufacturing capability limits the flexibility and agility required by the modern business supply chain,” Chappell says. With these upgrades, “Manufacturing becomes a strategic asset with the agility and flexibility to support business needs.”
Make2Pack met and reported progress at WBF’s March meeting in Atlanta.
Mark T. Hoske , Control Engineering editor in chief, MHoske@cfemedia.com
Help shape the future standard
Make2Pack is a joint working group of WBF - The Forum for Automation and Manufacturing Professionals, the OMAC Packaging Workgroup, and the ISA SP88 committee. Charter is to better integrate “making” and “packing.” Members are leveraging ISA-88 batch standard and PackML state model to develop ISA-88 Part 5. There are ties to manufacturing execution system (MES) in-formation access and ISA-95. For information on joining, contact David Chappell via www.wbf.org under working groups.