The emergence of Ethernet has seen its adoption not only in the Enterprise but also in the Production environments. It was first used for inter-PLC communication back in the 90’s, and now more recently for PLC-to-instrument (Fieldbus) communication. This widespread adoption of Ethernet fuelled by the need for greater visibility of the production process has resulted in increased demand for the integration of business operations and production control networks.

ANSI/ISA 95 was developed to define the interfaces between the Production and Enterprise functionality so as to reduce the risk, cost and errors associated with information exchange between these functions. To appreciate the importance of the ANSI/ISA 95 standard and more generally the challenges involved in integrating Enterprise and Production networks, one must appreciate the contrasting requirements and risks.

The first key differentiator between an Enterprise and Production network is the potential impact for either being compromised. In the case of an Enterprise network, the risk primarily relates to the acquisition or dissemination of private or sensitive information. In contrast, the risk of compromising a Production network relates to the loss of production, or worse – physical damage to assets.

The next key differentiator is network performance requirements, specifically throughput, latency and availability. The Enterprise network typically transports large amounts of data periodically or irregularly, however does not require particularly low latency or high availability for the transfer of this data. In the case of a Production network, the throughput requirements are typically much less, though low latency and high availability are critical for production.

The final key differentiator is the design life of an Enterprise network versus that of a Production network. The equipment in an Enterprise network is likely to be refreshed periodically with the arrival of newer Enterprise technologies and applications. The network equipment would be expected to have a lifetime of around 5 years. In a Production environment, however, the network equipment would be expected to have a lifetime closer to that of the production plant itself – around 15 years.

Also, there is the need for the maintenance of a Production network to be non-intrusive as even a brief outage translates to an immediate loss of production and results in additional delays to reinstate production. By contrast business operations are more tolerant of outages in its Enterprise network.

The integration of Enterprise and Production networks is not a trivial undertaking however there are significant whole of business benefits. These include initial CapEx and OpEx savings through the deployment of one physical network and increased visibility of the Production process resulting in better planning and scheduling.