The ISA95 standard from the Instrumentation, Systems and Automation Society (ISA, www.isa.org) has defined the required pieces to these problems. The standard includes a functional and object model, terminology, methodology and a subsequent common data schema.
Customers have demanded a lower total-cost-of-ownership for application-to-application interfaces. Their dream of an integrated suite of applications has been thwarted by perceived inaction of vendors and lack of a standard. Another part of the problem lies in the existence of many legacy systems that use proprietary data models and terminology. Consequently, mapping of data (tags, forms, types and frequency) between applications has been the root-cause problem.
In 1988, Dr. Ted Williams, Ph.D, of Purdue University, began the 15-year process of developing a working solution for integrated manufacturing—namely a foundation for standardized data schema and workflow. His work led to the development of the current three parts of ISA95, “Enterprise-Control Integration” Standard. The standard addresses the interface or exchange of data between enterprise systems (planning, scheduling, procurement) and production management systems (production dispatching and execution).
Parts 1 and 2 of ISA95 describe the boundary between Level 3 and Level 4, that is, of the enterprise and manufacturing levels of an organization, the general functions within the boundary and the interfaces to the boundary. Part 3 defines the internal elements and their interrelations (workflows) within Level 3.
In parallel, the four parts of the ISA88 Standard (Batch Processing Model) and the Business-to-Manufacturing (B2M) eXtensible Markup Language (XML) schemas for ISA88 and ISA95 have been developed. The two standards have evolved, matured and converged to a point where Parts 3 and 4 of ISA88 directly map into Part 3 of ISA95 as framework for a working solution. This is important, because the current ISA88 efforts on Part 3, “General and Site Recipe Models,” and Part 4, “The Batch Record,” address how ISA95 Part 3 workflows are to be executed and recorded/archived, respectively.
Translation standard
ISA95 is quickly becoming the tool for communication between the corporate cultures of production, information technology, finance, maintenance, procurement, quality and engineering. Each has its specific terminology and is now able to use the standard to translate.
The standard committee and technology providers are in the process of developing best practices with which to model manufacturing processes and workflows. Today, the basic use of ISA95 within a manufacturing company is to characterize the internal and external process flows (data flows and schema) between the production and enterprise workflows. This is typically a very difficult task. The organizational structure and the supporting workflows of most companies do not tightly fit the standard’s functional and object models. These vary dramatically across companies, depending on vertical industry, process type.
The functional and object models of the standard provide a starting point for communication and defining the baseline of a company’s specific process flows. Production analysts and engineers, corporate information technology strategists and business analysts now have some tools to enhance joint development of integrated systems.
Companies are finally recognizing that production workflow and data flows must be identified, streamlined and optimized through Lean Manufacturing and Six Sigma techniques. Performance metrics and their cause/effect relationships (compromises) to workflow are being developed and built into computerized systems with ISA95 as the enabling tool.
Charlie Gifford, [email protected], is business development manager for Oakville, Ontario, Canada-based systems integrator Aseco Integrated Systems, and a member of the SP95 committee.
