When is the right time to upgrade your control system?

Convincing management that it is time to upgrade a control system is a difficult prospect, indeed. There is the time and money spent in preparing for it, there is the funding required for the implementation itself and there is the lost revenue associated with the downtime. This is made more difficult than many other possible capital expenditures since there is typically little or no return on investment (ROI) argument to be made. This results in a situation where doing nothing is a very strong competitor to your upgrade project.

There are several inflection points in a control system’s life cycle that can be pointed to as key moments to consider an upgrade. These inflection points surround four different aspects in the support of a control system: spare parts, supplier support, configuration capability, and expertise availability.

Inflection Point: Spare Parts

When a new hardware line is introduced, most manufacturers provide stock in a factory warehouse and often in local distribution partner warehouses. This supply of parts can be used to quickly remediate a downtime situation without having to stock spare parts at your factory. As a hardware line ages and a replacement line is introduced, these manufacturers will draw down their stocks, and may move it from active inventory to a service-only channel. This may mean that system expansions are only permitted after discussion with the manufacturer sales representative or service management. This reduction in the ability to expand your control system is the first inflection point. Typically, this is not when a modernization is done, though if a large expansion is envisioned in the future, it may be appropriate to migrate the existing system first.

After a product line is declared obsolete or end-of-life, the manufacturer typically sells the remaining stock of hardware over the following several years. Typically, the amount of time spares are available is 3-7 years, though individual components may become difficult to find sooner. This is typically the most common time to consider a hardware migration to new components. In other cases, the control system owner will elect to maintain spare parts inventories at levels higher than likely usage. As their spares are drawn down, systems are modernized, putting the old components back into the spares inventory. Eventually, spare parts are not readily available even from after-market sources. Selecting this inflection point requires careful monitoring of your spares. The advantage is that for a large plant, spare parts usage should give a range of likely dates that hardware upgrade is required by. Furthermore, the spare parts usage and unexpected downtime has a dollar value associated with it – one that can be used for an ROI calculation.

Inflection Point: Supplier Support

New systems are actively supported by manufacturers. This is typically through support contracts, though some offer technical support and patching for free. After the software packages that support a hardware installation are removed from active support, it is common for the manufacturer to still offer technical support. As time goes by, obsolete support may be only offered at an increased price. Furthermore, support from manufacturer’s field engineers may become more difficult to secure if and as engineers get promoted, and new engineers do not have opportunities to work on old systems. These two points- inability to access manufacturer support, and increased support contract cost – form two more inflection points.

Inflection Point: Configuration Capability

This inflection is primarily caused by the depreciation and obsolescence on the combination of hardware, software, and operating system used. While there can be multiple inflection points, each tends to be centered on obsolescence of an operating system – such as Windows XP – and the resulting inability to support your control system without an old programming laptop. The situation may be compounded by incompatibility of drivers with newer systems. For example, while you may be able to create a Virtual Machine (VM) of WindowsXP to run on your new Win10 laptop, you may have issues with required serial port drivers that cannot run on the host machine. Furthermore, even if something seems to work, tech support teams may decline to troubleshoot your unsupported configuration.

Inflection Point: Available Expertise

Typically, expertise on a particular control system is attained either internally, from your local integrator, or from the manufacturer. It is easiest to recognize that a retirement of your long-term and much beloved control engineer will leave a skills gap. It might be harder to recognize that the replacement he was training may be one of very few people who know an outdated and obsolete technology. Your local system integrator likely has controls engineers on staff who have knowledge of older systems. These individuals may be available only at a premium or have delays in freeing up for non-emergency projects. Typically, manufacturers no longer train new service personnel in programming and maintenance for obsolete systems. As time goes by, the service person you may have called on is likely to be promoted, move to a different role, or retire.

If you have read this far, you can tell there are a number of inflection points, all of which interact to provide insight into when it is time to upgrade your control system. On careful examination, it is clear that many of them converge into two events: the manufacturer moving the status to end-of-life; and, before that the preceding manufacturer announcement. When you receive this announcement, it is prudent to begin your migration strategy, including budgeting, planning phases, and determining spare parts needs. When the platform is actually placed in an obsolete status by the manufacturer, you can migrate your systems according to plan, before running into issues around personnel and extended unplanned downtime.

ACE can help plan your control system modernization, regardless of your control system’s current lifecycle milestone. Read more about modernizing your system with ACE here.