When to Implement Improvements on Control System Modernization Projects - Emerson Automation Experts

When to Implement Improvements on Control System Modernization Projects

Emerson's John Dolenc

Author: John Dolenc

Many times modernization project justification is made up of several smaller optimization projects that are added together to reach enough financial benefit to justify the project. One of the interesting discussions we have internally amongst the consultants is when optimization projects associated with control system modernization should be implemented.

Some consultants say that the optimization projects need to be done during the modernization or they will never be done. This is a very good point. During the project there is deep involvement of multiple resources within the User’s organization that are necessary for the scoping and implementation of an optimization “project.”

Also engineering services are available both from both the User and engineering organizations. But the biggest reason is that once the modernization project is completed, the engineers are put on other projects and the operational organization becomes focused on the day-to-day activities of operating the process unit. All very good arguments.

The other side is that the most important goal of a modernization project needs to be that the process unit starts back up and is producing in-specification product on schedule after the cutover to the new system. This means the cutover needs to be planned very well and the emphasis is on ensuring the installation work is done correctly including: the wiring termination, correct communication and ranging of all field devices, and the expected function of the control strategy.

Straight forward improvements in control strategy should be implemented in the initial work, including the addition or upgrading of field devices. This is especially true for batch processing control logic improvements. However, careful consideration needs to be given to make sure that too many optimization improvements are not done, to cause the start-up of the process unit to be delayed. This implies that the small optimization projects need to be prioritized based on the financial payback and their difficulty to implement.

The remaining optimization projects are then implemented based on opportunities to develop, configure and implement the improved control strategies, and add any new field devices if required. To be sure, a disciplined plan to implement the projects needs to be followed.

Of course, much of the implementation timing strategy will be based on the justification developed for the modernization project. The timing of the when financial benefits will be obtained needs to be considered for the financial analysis. For example, for a Net Present Value analysis, the later the benefit is realized, the lower the NPV value will be, therefore a longer payback period.

There is no right or wrong answer between the two philosophies. Just make sure the objectives are understood, the risks are understood, and as much upfront engineering is done as possible.

From Jim: You can connect and interact with other control system modernization and migration experts in the Improve & Modernize group in the Emerson Exchange 365 community.

One comment so far

  1. jonasberge says:

    And, when you modernize your plant take the opportunity to make sure your HART devices work for you. All plants have smart devices with 4-20 mA/HART. However, in most plants digital HART is only being used with the handheld field communicator. The control system only uses the analog 4-20 mA signal. HART is usually not used by the control system or from Intelligent Device Management (IDM) software part of the Asset Management System (AMS). Many plants were even built with the intention to use the HART communication, but for various reasons it did not materialize. There are several reasons why HART has not been put to good use in every plant. Learn how to put HART to work:

    Some points include:
    -Lack of training
    -DCS AI cards have no HART pass-through
    -The 4-20 mA cable not meeting HART requirements
    -Safety barriers chosen are not HART compliant
    -Signal wires mixed with power cables
    -Shield not continious
    -Device not grounded
    -Shield not grounded
    -Shield grounded in many places
    -DCS AI cards affected by HART
    -DCS AO cards affecting HART
    -Device does not have DD file
    -DD not loaded on system
    -Noise DC power supply
    -Master conflict
    -Burst communication conflict
    -HART version 7 incompatibility
    -Command 48 missing in device
    -Device not HART registered
    -Instrument diagnostic alarm management not engineered
    -DCS AO tight-shutoff set to 0 mA
    -Cable armor not grounded
    -Cable/wire damage
    -Corroded terminals
    -HART integration test not done at FAT
    -HART not tested during loop check
    -IDM software not incorporated in standard operating procedures
    -Network health not monitored

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