If you're upgrading your automation system, or considering doing so in the near future, your focus might be primarily on the human-machine interface, controllers, and I/O interfaces. This is correct, as these are critical components during system migration. However, an automation system involves more than just these hardware components. If these secondary aspects aren't given sufficient attention during the planning phase, they can cause numerous problems.
Conducting a Preliminary Preparation Scale (FEL) assessment before undertaking any significant automation upgrade project is one of the best ways to examine all aspects of the automation system. An FEL assessment is an analytical technique used to evaluate various aspects of an automation system upgrade or other project.
Due to a lack of manpower, most end users complete FEL assessments in collaboration with external service providers. A good, suitable service provider should be able to perform FEL assessments for many automated system upgrade projects, thus helping end users complete a thorough study in an optimal way.
FEL assessments help with budgeting and provide data for project validation. They also expose potential problems, aiding in the daunting task of migrating outdated DCS or PLC-based automation systems. In short, it offers a shortcut to success.
In most cases, the time and effort invested in FEL assessment is directly proportional to the success rate of the entire project. Unfortunately, many end-users view this phase as an optional task during automation system upgrades, sometimes even as a burden. Reducing investment in FEL assessment not only increases risk but also forfeits opportunities for improvement and enhanced long-term stability. Conversely, a thorough FEL assessment identifies potential problems, which helps ensure project objectives are met.
In the early stages of an automation system upgrade project, smart meters should be connected to the new automation system and their compatibility tested.
10 factors that cannot be ignored
Once the main structure of an automation system upgrade is developed, the key components typically include the human-machine interface, controller, and I/O interfaces. During the planning and budgeting phases, most time and effort are spent on these critical components, which may negatively impact auxiliary systems outside the main system. Table 1 lists 10 key aspects that require careful attention for a properly performed FEL assessment, which will be discussed in detail below.
On-site equipment and infrastructure
Field equipment and wiring mainly consist of four parts:
Cables, conduits, and conductor troughs;
Panels, cabinets, grouping panels, and junction boxes;
Instruments, including embedded devices, analytical instruments, sensors, etc.
Mechanical equipment, including electric motors, valves, actuators and other field equipment.
All these items should be inspected to determine acceptable physical condition and applicable documentation. Furthermore, instruments and machinery must be inspected and tested to ensure proper connectivity with the new automation system's I/O and digital communication interfaces.
During the FEL process, the overall condition of field wiring, including terminals, labels, and grounding, should be assessed. If any aspect fails to meet standard requirements or is not in good working order, appropriate plans and budgets should be developed to correct any deficiencies and defects.
Various field devices, such as motors, valves, and limit switches, are hardwired to the input terminals of the automation system. Once the automation system is powered on and running, the status of each component can be determined. Therefore, it is essential to test the interfaces between these devices and the inputs to ensure appropriate voltage levels and electrical isolation.
Similarly, valves, motors, and status lights are driven by the outputs of the automation system. Compatibility must also be ensured so that each output can drive its corresponding device.
The interface with analog I/O in automation systems can be a problematic area. In a loop connection, a 4-20mA output from an older automation system might drive more instruments than a 4-20mA output from a newer system. This is a minor issue if discovered during FEL evaluation, but a major one if found during commissioning. Furthermore, compatibility checks and sometimes testing of analog inputs are essential. For example, thermocouple types suitable for older DCS systems may no longer be widely used and therefore not supported in newer automation systems.
Most factories connect smart meters and analytical instruments to their automation systems via their own networks, which is another aspect that must be carefully considered during the FEL evaluation process.
Network infrastructure and connectivity
Modern automation systems connect with a range of other systems and components at different levels, including:
Control layer: Auxiliary control systems, emission monitoring systems, building automation systems, etc. in process units;
Enterprise layer: historical database, MES, ERP, company network, etc.;
Field device layer: HART, Fieldbus, Profbus, DeviceNet, etc.;
Other: laboratory systems, remote access, analytical instruments, advanced process control equipment, etc.
The physical infrastructure, including the fiber optic/copper backbone, network equipment, wireless hardware, and other items, must be inspected to determine acceptable physical conditions and applicable documentation. As with compatibility issues, even if the new automation system supports nearly the same protocols as the legacy system, this is only the first step.
To ensure proper communication, key interfaces should be tested at each level to ensure their performance equals or exceeds that of existing systems. Whether communicating directly or via protocol converters, the new automation system must support all existing communication protocols. In some cases, upgrading or even replacing systems or components that cannot interface with the new automation system may be more economical.
For example, if a small number of instruments use a different fieldbus protocol than the vast majority of instruments, a better approach might be to replace these "outliers" rather than adding a protocol converter to connect them to the new automation system.
In older automation systems, controllers and smart devices, such as meters and drives, are often supplied by the same vendor. If a new automation system is procured from different vendors, even if it uses the nominally same communication protocol, in most cases, its digital interface with the smart meters will have many functional limitations. When operating these functionally limited systems, contingency plans must be developed as early as possible, or the smart devices must be replaced.
Auxiliary systems and space requirements
The components of the new automation system should be located in a specific area, typically the main control room where the old system was located. The following aspects should be checked to ensure that this area meets the requirements of the new system specifications and subsequent operation and maintenance:
Power requirements, including UPS;
Air conditioning system requirements;
Physical space layout requirements;
Human factors engineering in the main control room.
UPS and other power systems must have sufficient capacity to handle new automation system components. Similarly, air conditioning systems must keep new electronic equipment cool while maintaining a comfortable working environment for operators.
Sufficient overall space is required to arrange and install new system components, including control hardware and operator stations. Many control consoles from older automation systems cannot be used in new automation systems, or even if they can be used, they must be significantly modified.
One often overlooked aspect is the commissioning schedule and its impact on auxiliary systems and space requirements. Many new-system migration commissioning schedules require both systems to operate simultaneously. Clearly, this has significant implications and necessitates careful planning to accommodate concurrent operation of both systems. This typically requires temporary additions of auxiliary power systems and transitional installation space.
Key documents
The installation of the new automation system, including all interfaces and connections with field devices, network infrastructure, and auxiliary systems, requires many changes to documents and drawings.
To ensure the successful operation and maintenance of new automation systems, certain key documents must be reviewed and updated regularly. Some of the most important documents include P&ID diagrams, control loop diagrams, I/O databases, system configuration files, software programs, software documentation, patch requirements, functional specifications, control system manuals, and programming and design specifications.
Dismantling, installation and commissioning
A thorough FEL assessment requires reviewing the necessary dismantling, installation, and commissioning services to ensure these activities are considered in terms of budget, planning, and human resources. Production facilities are typically staffed for daily operations and may not have sufficient personnel to carry out large-scale engineering projects. Therefore, the FEL assessment should identify the required personnel and prepare for the hiring of additional staff.
The commissioning plan is a critical part of any automation system upgrade. Generally, key items to list include downtime plans, plans to minimize downtime, and utilization during the hot migration of the old and new systems. Additional personnel may be required considering other installation and commissioning-related activities. Contingency plans should also be developed to address any reductions in production output during installation and commissioning.
During the FEL assessment, construction and design activities related to installation and commissioning should also be reviewed and planned to ensure their proper execution. Key activities to be implemented include developing new cable and cable tray plans, instrument and field equipment drawings, panel and cabinet designs, circuit diagrams, motor schematics, point location diagrams, and detailed installation drawings.
Compliance and Abnormal Situation Management
Changes made to accommodate upgrades to automated systems need to be reviewed to ensure they meet standards, regulations, and operating procedures. Safety Instrumented Systems (SIS) must be reviewed to ensure they maintain all Safety Indicator (SIL) levels. Layer of Protection Analysis (LOPA) is required, and environmental health and safety protocols must be maintained at acceptable levels.
Current standards and regulations such as those of NEC, NFPA, and FDA must be met, and sometimes licenses and inspections are required under NEC and NFPA regulations. Similarly, FDA regulations for validation systems contain very stringent provisions that must be followed when making any changes to equipment used in drug production. Many food and beverage plants must also comply with FDA regulations when making modifications and upgrades, although the standards are often lowered.
Legacy automation systems have certain informal or formal mechanisms for handling abnormal operating conditions. Similarly, new automation systems must also have mechanisms for handling abnormal operating conditions. Improvements can often be made in this area by simply leveraging features built into the automation system, while utilizing existing standards and best practices for abnormal condition management, graphical and alarm management.
In fact, FEL should evaluate all possible areas for improvement, including ASM, as this will ensure the maximum return on investment in the new system.
Improvements
The features and functions of new automation systems are generally absent in outdated DCS or PLC-based systems, which allows for improvements to existing operations. Upgrading automation systems provides an excellent opportunity to improve existing operations and practices, thereby achieving further enhancements.
The main aspect of the improvement is converting processes and systems that were previously operating in manual mode into automated control. If manual operation is still necessary due to a lack of sufficient parts or equipment in the factory, then that equipment needs to be upgraded or replaced. For example, to achieve automated control of a specific loop, on/off valves need to be modified or replaced to function like control valves.
In other cases, areas where automation is difficult to achieve in older systems may become automated in newer systems. These new systems typically have built-in advanced process control features, enabling them to automatically control complex loops. Shifting from manual to automatic control reduces the need for operator intervention, thereby minimizing human error, preventing downtime, improving production, increasing output, and resulting in both short-term and long-term returns on investment.
Many older automation systems provide data and images to factory operators using outdated graphical displays with low resolution, poor screen quality, and insufficient screen size. In contrast, new automation systems can take full advantage of the significant advancements in operator interfaces, hardware, and software over the past few decades to reduce operator fatigue, facilitate the training of new operators, and improve the management of abnormal operating conditions.
Upgrading an automation system means replacing an outdated system with a more user-friendly and maintainable one, which also presents an ideal opportunity to improve operational performance. Simply making a similar replacement would miss a significant opportunity. To fully capitalize on system upgrades and mitigate risks, a thorough FEL (Fulfillment by the Controller) assessment must be conducted, examining all aspects affected by the upgrade, including those beyond HMIs, controllers, and I/O.
