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NOV-DEC 2017

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FACTORY AUTOMATION standard event record definitions, so all information receivers apply only a single structured interpretation of the operations event. l An operations profile method (ISA- 95 Part 8, Manufacturing Opera- tions Profiles, Working Draft 02) de- fines the reusable operations event definitions across messaging imple- mentations. l An operations profile represents a de- scription of the information exchange semantics for the scope of a defined process, workflow, industry, and cor- porate scope (Levels 2, 3 and 4). l Each operations event message (and ISA-95 exchanges in general) is exe- cuted and validated to an operations event profile in an operations profile. Operations event defined ISA-95 Part 2 defines an operations event as a notification of manufactur- ing operations action (production, quality, maintenance, inventory move- ments) that occurred within an activ- ity, function, task, operation, or phase. Not all real-world events warrant the manufacturing system creating an op erations event message. Examples of operations events are: l completion of an activity function or task (work schedule created, re- leased, or dispatched) l completion of a business process step (job order started or completed, operations schedule created, re- leased, or dispatched) l resource status changes (i.e., re- source acquired, released, available, committed) l physical process step actions (i.e., ma- terial lot created, updated, deleted) l The current data exchanges between manufacturing systems primarily emphasize synchronous (request/ response) data-centric transactions based on a dated notion that net- works cannot provide guaranteed message delivery. The result is: ° The existing receiving systems and controllers require processing logic to interpret multiple data-centric messages for an event. ° Data-centric messages are fre- quently received or processed out of order, lost, or delayed. ° Receiving systems process incor- rect event data when executing their functions to produce bad decision making. ° Data-centric exchanges do not provide a consistent package for the complete process, operations event, or the exception as re - quired for the IIoT or the Industry 4.0's cyber-physical connection. l Manufacturers require more flexible, extensible manufacturing opera- tions and automation data exchange models for out-of-the box configu- ration of intraplant data exchanges (not custom mapping) to meet spe - cific event-driven requirements. Solution l Real-time messages interoperate across existing heterogeneous mes- saging and system implementations. This is the operations event publish- subscribe message provided by an industrial event-driven architec- ture across process control/SCADA, MOM, and enterprise resource plan - ning (ERP) systems. l IIoT interfaces as lightweight asyn- chronous event-driven sematic formats and com- munications are designed for the timing required to support real-time cyber- physical connections of operations events. l A single operations event message shall contain all changed data for the event. l An operations event mes- sage shall be self-describ- ing based on reusable 26 INTECH NOVEMBER/DECEMBER 2017 WWW.ISA.ORG ISA-95 Operations Event Model The overview of the Operations Event Model (figure 3) illustrates how the up- dated Part 2 standard defines operations event message occurrence by the ex- changed objects for the operation event definition and operations event defini- tion class, which are documented in an operation profile for a specific process. This pattern follows the same structure used in the ISA-95 Material Model. l Operations event: The object noun for an instance that contains the changed data for the event published within a notify transaction of the Notification Model. l Operations event definition: The for- mal, explicit operations event defini- tion for the event occurrences, op- erations event. The definition of the operations event message is transmit- ted by the provider to consumers and subscribers. Typically, many events are transmitted that follow a specific defi- nition. l Operations event class: Operations event definitions may be grouped by common meaning or structural com- ponents into an operations event class. l Operations event profile: The opera- tions event classes and operations event definitions are typically speci - fied in a plant's user requirements and associated system functional specifi - cations as an operations event profile or similar reusable form as a descrip- tion of the information exchange se- mantics for a defined scope. It also enables message partitioning to avoid name clashes and allow cooperation of message specifications from differ- ent sources in implementations. This Figure 3. Structural overview of the Operations Event Model

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