Deciding Upon Control-System Technology

When buying ethanol plant control technology, manufacturers face a number of important considerations that will have a major impact on the success of their project over the long-term. Contributing writers Hans Alwin and Dustin Howe, of Swanson Flow Systems, outline the primary factors and technology requirements involved in making a solid purchasing decision.
By Hans Alwin & Dustin Howe, Swanson Flo-Systems | September 01, 2003
Control-system technology, sometimes referred to as process-control automation, is a constantly evolving facet of ethanol production. Innovative solutions for optimization, advanced control and predictive maintenance of control systems is likely to provide continuous improvements in production efficiency.

Presently, "control functionality" of many automation systems on the market is limited, making the selection process a comparison of technologies. Still, selecting a new control system as part of a plant modernization, expansion or greenfield project is more than just a technology decision. Users should also consider factors such as system architecture, enterprise integration, vendor experience, customer support and ease of future system upgrades.

When navigating a decision for a new control system, manufacturers face a number of important considerations that will have a major impact on the success of their project over the long-term. The following is a brief discussion of key purchasing decision factors, including:
Primary Considerations, Vendor Selection and Technology Requirements.

Primary Considerations
Project Methodology

A primary automation contractor can act as the principal on a project, by providing single-source accountability. An automation contractor's familiarity with the integrated control solution ensures that the user gets the greatest benefits out of the new technology. In the role of the main automation contractor, the control vendor provides or obtains all necessary automation equipment and oversees design, engineering, installation and commissioning of the new system.

System Integration
Companies wanting to unite the worlds of process and business should choose an automation solution that allows them to establish a single, global database for all manufacturing information. This database must be available to all interested users, and easily accessible from the supervisory to the operator level. The solution should also include applications that synchronize the database with the business environment.

Vendor Selection
Established Technology

When it comes to selecting a control system provider, bigger is usually better. The provider should offer an expansive, well-supported product portfolio or at least have in place strategic alliances with the third-party suppliers in order to meet the full scope of the customer's automation requirements.

The supplier's control-system platform should be based on a flexible, nonproprietary architecture that can deliver vigorous process control, unlimited connectivity, reliable safety and seamless encapsulation of installed systems. The supplier should also offer a suite of applications supporting advanced process control (APC), optimization, asset management, Six Sigma methodologies and other business-driven initiatives. In addition, the supplier should provide all of the instrumentation, control devices, value-added programs, services and training necessary to support their solution.

Always keep in mind that an automation provider may offer a state-of-the-art computing platform but fall short when it comes to integrating advanced tools and applications in its solution. Applications must then be purchased separately and "bolted-on" to the system.

Domain Proficiency

When evaluating prospective control-system providers, domain proficiency is quite often one of the most important criteria. Only a supplier with a proven and demonstrated understanding of your industry, company and business can help you succeed.

The chosen supplier should have different branches, teams and consultants that are all focused on your market. They should be capable of deploying a project engineering group familiar with your production strategies, knowledgeable about your business practices, and able to apply automation technology to improve financial results.

A supplier with enduring customer domain proficiency can also uncover implementation cost savings. This supplier will ensure their project proposal covers all of the bases, thus minimizing change orders and resulting in a proposed initial price and finishing price that are relatively similar.

Application Knowledge
After establishing your supplier's domain proficiency, the next factor to consider is application knowledge. As your automation partner, the control-system supplier must have a sufficient knowledge of your manufacturing processes to effectively apply advanced control strategies, and then put this knowledge to use improving plant efficiency and business performance.

Joint Accountability
Automation providers who believe in joint accountability are so confident of the benefits of their solution that they are willing to join you in sharing risks. Rewards to the provider come from sharing in financial results attributed to improved manufacturing performance.

In this type of business relationship, rather than the customer devoting capital to control-system purchases, the supplier owns, installs and maintains all plant automation equipment. This includes updating technology as needed to capture the largest performance benefits. The supplier also assumes control-related payroll costs, and is responsible for recruiting, employing and training support personnel for the automation solution.

Contracts based on joint accountability remove the risks and costs of process automation from the customer. Furthermore, they eliminate budget constraints that keep users from modernizing their control-system architecture.

System Improvements
Pay close attention to whether potential suppliers provide a secure, affordable migration path to the latest technology. Too often, customers invest in physical and intellectual assets, only to find out that their supplier has stopped supporting, or has even discontinued a particular control-system architecture. This can require an entirely new and expensive program to replace your previous one.

Wise automation providers tend to construct investment protection guidelines that help customers leverage the value of their existing assets. Some offer integration tools that supply operators with a common view of data, applications, alarms, events and messages across different platforms. Consequently, new and legacy systems can coexist while the customer migrates – at a pace they determine – to the latest control technology.

Support Assistance
In the competitive process-control field, a vendor's success hinges not only on the performance of its system solution, but also on the quality of its support services. Despite rapid changes in automation technology, suppliers must be willing and able to support legacy equipment dating back 10, 20 or even 30 years (relatively old analog systems and instrumentation are still the norm in many plants).

Automation vendors should provide services offerings that support and protect their customer base, such as service contracts to allow customers to lock-in their automation budget at a fixed rate over an extended period of time and guaranteed hardware and software upgrades to keep technology up-to-date.

Technology Requirements

Control Architecture

Choose an open, scalable control system that is fully redundant, includes robust control algorithms, and provides on-process upgrades to minimize plant downtime. The system should be embedded with the best-in-class applications for advanced control, asset management and control monitoring, and include a human interface integrating plant-wide information and delivering real-time process data. Additionally, the system should comply with open industry standards.

Field Instrumentation
Process Industry users are now seeking control solutions that support digital integration of field instruments, allowing processes to be linked with monitoring and control equipment and providing the platform needed to operate plants more profitably.

However, increased implementation costs for installing fieldbus technology in all areas of the plant may not be justifiable for some users. Some processes simply do not warrant the added capabilities of smart field devices. For this reason, your automation provider should offer a maintenance-management program incorporating all of your field assets – traditional and fieldbus alike – and providing tools for integrating all device information in a single database.
System Networks

Control systems employing open network protocols provide process plants with new levels of connectivity. Users have the freedom to select the best control and instrumentation solutions for a given task. They can mix and match devices from a variety of manufacturers and transparently integrate them in a field network strategy that suits their needs.

Be sure the control system you choose makes full use of recognized open standards and is equipped to integrate the industry-leading field network protocols. These include Foundation fieldbus, Profibus, HART, DeviceNet and ControlNet, among others.

Optimization Solutions
Increased competition is causing manufacturers to look for ways to squeeze additional productivity out of their operations. This requires a solution that redesigns work processes across the enterprise to get the most out of your personnel, processes and technology.

When selecting a new control system, it is important that the vendor offer a solution capable of accommodating optimization, multivariable control and APC. In this manner, you will have access to the information needed to involve the right people in the process, at the right time. You will also have a methodology in place for continuous improvement.

Predictive Maintenance
Asset-management systems are designed to support a reliability-centered maintenance program, automated decision support for identification and repair of equipment problems. Benefits include increased plant availability and uptime, focused maintenance efforts and reduced equipment failure.

Users should determine whether a supplier's asset-management solution is "field centric." A field-centric solution relies on device diagnostics to enable preventative maintenance on valves, transmitters and other intelligent instruments. Although a good first step, this approach does not provide an understanding of how device status impacts process performance.

With a process-centric solution, users have an enterprise-wide view of the relationships between all installed assets, and as such, can make informed decisions affecting plant availability. This approach allows the user to determine: 1) the impact of equipment problems on the process; 2) the association between these problems and the business; and 3) the priority of need repairs. EP