July/August 2011

International vertical integration standard expands scope

By Bianca Scholten

If you are involved in laboratory information management systems (LIMS), warehouse management systems (WMS), or asset management systems, listen up. The ISA95 committee has expanded the scope of ISA-95.00.01 and ISA-95.00.02 (also known as ISA-95 Parts 1 and 2). The advantages include more generalized models to include lab, warehouse, and maintenance departments and to allow companies to integrate LIMS, WMS, and asset management systems with each other as well as with enterprise resource planning (ERP) or management execution systems (MES).

After publishing an American National Standards Institute (ANSI) standard, ISA either reaffirms, revises, or withdraws these standards. For Parts 1 and 2 of ISA-95, the Enterprise Control System Integration standard, the committee decided to revise, resulting in a large extension of the scope.

In May 2010, ISA published the new versions. The first versions especially focused on developing interfaces between ERP and MES systems. The new versions enable manufacturing enterprises to apply ISA-95 to integrate their LIMS, WMS, and asset management systems with their ERP solutions. Here is a brief overview of the most important changes in the second versions of ISA-95, Parts 1 and 2.

Production to manufacturing

Version 2 of Part 1 has only minor changes compared to Version 1. The most important adjustment included moving some models from Part 3 to Part 1. The ISA95 committee thought it should present general models, such as the Manufacturing Operations Management model in Part 1. Remember, Part 1 provides models and terminology you can use as a basis in projects that integrate enterprise systems with control systems.

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On the other hand, the changes to Part 2 are significant. Take a look at the first figure (above) to understand what has changed. The Manufacturing Operations Management model shows 12 functions (the white ovals) that manufacturing companies perform. Functions located outside the thick dotted line belong to the Enterprise domain. For functions such as processing customer orders (Order Processing) and purchasing all kinds of materials (Procurement), employees at the office often use ERP systems. Everything inside the field bordered by the thick dotted line belongs to the Control domain. Within that domain, four groups of activities take place-namely activities that focus on the production process, lab, maintenance, and warehouse activities. The first version of ISA-95 Part 2 contained data models that focused strongly on the exchange of information about production processes. The lab, warehouse, and maintenance department received little attention. In the new version, the models are more general, so companies can now use them to integrate LIMS, WMS, and asset management systems with each other or with ERP or MES as well.

Four data models, 16 information categories

In the Manufacturing Operations Information model (below), it is clear which data models ISA-95 provides for the exchange of information between ERP, MES, LIMS, WMS and maintenance information systems. We already knew the Production Schedule, Production Capability, Product Definition, and Production Performance models from Version 1. These provide information about when the factory has to produce which product, which resources are available to produce products, which products the factory can produce, and which ones the factory actually produced.

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The ISA95 committee used these production models as a basis and renamed them operations models. So there are not actually 16 models available (four for production, four for quality tests, four for inventory and four for maintenance). Instead, there are only four operation models available (Operations Schedule, Operations Capability, Operations Definition, and Operations Performance) we can use to exchange information about production as well as inventory, quality tests, and maintenance. How does that work?

Operations type

Take a look at the example of a simplified depiction of the operations schedule. In practice, the operations schedule can contain a production schedule, a maintenance schedule, an inventory schedule, a quality test schedule, or a combination of two or more of the aforementioned schedules. You can compare this model to a preprinted form with fields in which someone fills in company-specific data. For every rectangle (object) in the model, a few fields are defined. Tables in ISA-95 Part 2 provide an overview of the relevant fields, called attributes. For example, the object Operation Schedule has the following table:

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Note that for the attribute, Operations Type, you must decide whether this is a schedule for production, quality, inventory, or maintenance tasks, or whether it is a mixed operation. This field is mandatory. Almost every object in these new data models contains such an Operations Type attribute. This way, the committee enabled the application of four general models to 16 information categories.

What happened to production models?

The committee did not completely remove the production models from Version 1; they moved them to an annex. The committee advises using operations models instead of production models for new implementations. However they thought it would be valuable to provide the older models in some way because these have already been implemented worldwide and are less abstract. Therefore, you can use them as an example to make it easier to understand the more abstract operations models.

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Physical asset

We made more changes to Part 2. We cannot ignore the concept of a physical asset in this introduction to the new versions of ISA-95. This is an important aspect especially concerning maintenance information because we need to be able to differentiate between equipment and physical assets (see simplified operations schedule figure). A P&ID may show a tag number of a pump. From the viewpoint of production, this pump has the Equipment ID P1. The operator can see the ID P1 on his SCADA screen. Assume the pump breaks down, and the mechanics replace it temporarily with another pump. From a production view, this still is P1. It is not necessary to adapt the SCADA screen. But from a maintenance perspective, this is another pump with a unique asset number. For maintenance purposes, this individual pump has to be traced. Therefore ISA-95 added an object model for information about physical assets.

Practical applicability

When you really want to develop interfaces between the above-mentioned types of systems, you can use a combination of ISA-95 and XML, called business-to-manufacturing mark-up language (B2MML). The B2MML working group of WBF (the organization for production technology) has almost finished working on release v0500 of B2MML, in which the new models are available. We expect the new version of B2MML to be published this year. After that, suppliers of ERP, MES, LIMS, WMS, and maintenance information systems can adapt their standard interfaces. That still could take a long time. The most important challenge is suppliers of LIMS, maintenance information, and WMS solutions probably first need to learn there is something called ISA-95 before they start to adjust their systems to this standard.

For the newest versions of the ISA-95 standard visit www.isa.org. For the newest versions of B2MML, visit www.wbf.org. For basic information about ISA-95, read The Road to Integration: A Guide to Applying ISA-95 in Manufacturing, available at www.isa.org. ISA also has other books available about ISA-95.

ABOUT THE AUTHOR

Bianca Scholten is a principal at Accenture, a global management consulting, technology services, and outsourcing company. Scholten is a voting member of the ISA95 committee; she is also the author of two ISA bestsellers, The Road to Integration: A Guide to Applying ISA-95 in Manufacturing and MES Guide for Executives: Why and How to Implement a Manufacturing Execution System.