Guidelines for implementing ISA-88 in discrete machines
The widely used ISA-88 series of standards provides terminology and a consistent set of concepts and models for batch manufacturing plants and batch control. The standards, however, were not defined in the context of packaging machines or machines that perform discrete operations. As the ISA-88 standards continue to evolve, the context of models can be extended to include the entire plant, integrating the software definitions of batch, packaging, converting, and warehousing.
To that end, the ISA88 committee, Batch Control, has completed a revision of ISA-TR88.00.02, Machine and Unit States: An Implementation Example of ISA-88. Publication by ISA is planned for July 2015.
Current approaches in programming discrete machines are generally considered to be solely dependent on the machine and the software engineer or control systems programmer. This constant change offers little additional value and generally increases the total costs, from designing and building the process to operating and maintaining the system by the end user. The new technical report demonstrates how to apply the ISA-88 Part 1 standard concepts to automated machine states and modes. It gives examples of general and specific machine state models and procedural methods. It also cites real control examples as implementations, provides specific tag naming conventions, and cites a number of common terms that are consistent with batch processing and the ISA-88 Part 1 standard.
Alarm management standard revision underway
ANSI/ISA-18.2-2009, Management of Alarm Systems for the Process Industries, has found wide use across the process industry sectors. The standard addresses the development, design, installation, and management of alarm systems in the process industries. Alarm system management includes multiple work processes throughout the alarm system life cycle. The standard defines the terminology and models to develop an alarm system and the work processes recommended to effectively maintain the alarm system throughout the life cycle.
An International Electrotechnical Commission (IEC) version of the standard, IEC 62682, was published in late 2014. ISA18 co-chairs Donald Dunn and Nick Sands led the IEC work as convenor and secretary/editor, respectively. IEC 62682 eliminated country-centric criteria that were present in the original standard. In addition, there was a shift of the normative criteria (“should” to “shall”) within IEC 62682. The IEC work used a single editor (Sands) in lieu of clause editors as had been used in writing the original ISA-18.2, promoting a more cohesive document with consistent wording and terminology throughout.
In leading the IEC work, the ISA18 co-chairs elected to edit the ISA-18.2 standard by incorporating the changes implemented during the IEC work and then submitting the document to ISA18 for comments. For this reason, ISA18 is now well positioned to complete a revision of ANSI/ISA-18.2. A committee ballot on the revision was issued in mid-May, and will be completed in time for results and comments to be reviewed at the next face-to-face ISA18 meeting on 15–16 June 2015 in Raleigh, N.C., in conjunction with the ISA Leaders Meeting.
Also meeting at that time will be ISA18 Working Group 1, which will be reviewing input received in a recent review of ISA–dTR18.2.01, Alarm Philosophy. This technical report (TR) supports ISA-18.2 by providing guidance on how to implement the recommendations and requirements described in the alarm philosophy clause of the standard. It outlines potential approaches and provides specific examples that can be included in an alarm philosophy.
This document is one of a series of ISA18 technical reports that provide support in using the standard. Others in development by ISA18 include Identification and Rationalization (TR2), Basic Alarm Design (TR3), and Alarm Management for Packaged Systems (TR7).
Previously published ISA18 technical reports include:
- ISA-TR18.2.4-2012, Enhanced and Advanced Alarm Methods, helps users to evaluate when to use enhanced and advanced alarming methods, what benefits they can achieve, and what challenges and costs to expect.
- ISA-TR18.2.5-2012, Alarm System Monitoring, Assessment, and Auditing, provides guidance and information supplementing the standard on the use of alarm system analysis for both ongoing monitoring and periodic performance assessment.
- ISA-TR18.2.6-2012, Alarm Systems for Batch and Discrete Processes, covers the application of alarm management principles in the standard to batch and discrete processes.
For information about viewing or obtaining ISA standards and technical reports, visit www.isa.org/standards. For information about participating on an ISA standards committee, contact Charley Robinson, ISA Standards, firstname.lastname@example.org, +1-919-990-9213.