Managing an open system
The critical piece of managing an open system, therefore, is managing complexity to improve system security and reliability.
For all the benefits open systems provide, they also pose significant IT challenges. End users can only rely so much on their automation suppliers for support to keep process control networks secure. The reality is that plant engineers are now responsible for increasingly complex open automation architectures and the specialized IT support functions that go along with them.
With an open system, plants are able to use various products from multiple vendors to run their automation processes. However, this diversity adds complexity when trying to keep plants secure and running. The critical piece of managing an open system, therefore, is managing complexity to improve system security and reliability.
Deploying an open system
Deploying an open system requires designing a robust process control network that is compartmentalized with security zones based on the Purdue model or the ISA S99 standards. However, because it connects the plant floor to a LAN, the process control network can become vulnerable to cyber threats if appropriate precautions are not taken.
This is why it is critical to have business IT and process IT professionals work together to create a defense in depth (multi layered) and centralized security policy to maximize operational effectiveness.
Differences between process IT and business IT
Deploying an open system allows plant personnel to use a variety of business software applications that typically fall within the domain of business IT. However, business IT personnel are focused on enabling users to perform their business activities while maintaining the LAN and protecting the company's intellectual property, whereas process control regards human and plant safety as a primary concern. This is an important distinction to keep in mind when reviewing the following best practices in managing an open system.
Managing an open system
The key fundamentals of managing an open system include:
Vendor support - Vendors have the best practices and knowledgeable resources to support their systems, so you should establish a good working relationship and not expect to replicate all that knowledge on the plant floor.
Security assessments - It is folly to assume that even if you designed a secure process control network that it will remain so forever. Routine security audits will identify vulnerabilities that have occurred since the original deployment or that only recently were understood.
Change management - Day-to-day changes can easily get out of control and put your entire system at risk. It is critical that documentation remain current and just as important, that procedures be updated as changes in the system naturally occur.
Firewall management - Due to the vulnerability of the business's LAN, plant floors must implement a secure firewall on the perimeter of their process control network infrastructure. All entry points into the process control network should be known and strictly managed.
Virus protection - Keeping antivirus software up to date is extremely important to thwart virus threats. Plants must keep process control networks current with antivirus definition patches by using an automated but controlled process.
Patch management - Software patches are distributed regularly by application manufacturers to resolve insecurities found in system coding. Before installing patches, plant floor IT personnel must first verify they will not adversely affect the process by testing offline.
Data recovery - In determining the need for a data backup solution, it's important to first assess the impact of data loss, corruption and availability to the plant floor. Understanding the impact of data loss or unavailability can then be used to determine appropriate data recovery procedures including on- and off-site retention and testing of backups.
Interface management - Standards such as OPC allow for greater interoperability. However, it's recommended to limit the number of third-party devices on the plant floor, which reduces the number of upgrades needed to specific devices, and reduces time needed for testing and validation before putting offline equipment back in service.
System performance monitoring - The only way to effectively keep on top of the impact that all day-to-day activities have on your open system is to routinely monitor and trend key system performance parameters such as CPU free, free memory, hard drive space, bandwidth and errors.
Lifecycle management - One of the benefits of performance trending is to readily identify when performance requires a system upgrade. It is important to plan for system upgrades both for software and hardware, because the only way to keep your system secure is to maintain a supportable infrastructure.
In the past few years, open systems have gained increased acceptance and distinction in the process industries for their flexibility, allowing plants to select various automation control components to create customized automation systems. Additionally, they provide significant performance improvement and cost savings across the process control network. The challenges that go along with an open system environment can be readily overcome by a combination of assessing vulnerabilities; designing and implementing secure, effective networks; and through the ongoing management of these systems by teaming with the automation supplier to provide best practices and knowledgeable resources.
Shawn Gold is a global solution leader for Open Systems Services at Honeywell Process Solutions.