Will your executive board be surprised at the cost of
replacing your automation controllers?
Obsolete controls – every industrial organization deals with
them. Whether it’s manufacturing, mining, oil & gas, water/waste water, or
building automation, electronic controls don’t last forever and eventually need
replaced. I suspect many companies are facing this issue now, particularly as
it concerns their programmable logic controllers (PLCs). IEC 61131 (the
international standard for PLC programming) was first introduced in 1993, and
standards-based devices soon followed. Many of those devices have been in
operation for two to three decades, which means we are now in the midst of
first-generation controller replacement. This is sparking numerous
conversations on social media, such as this one on LinkedIn’s Automation group forum: “What
about automatically converting PLC software from one system to another”.
It’s clear we are reaching the end of the era where machines
were isolated cells of production; modern automation is expected to be far more
integrated into the business processes in ways first generation controllers
were not capable – leading to “programmable
automation controllers” (PAC). They must provide data to facilitate
maintenance. They must interact with enterprise resource planning,
manufacturing operations management, and product lifecycle management systems.
They may be required to collaborate with other machines, materials management
systems, robotic systems, and quality management systems as well. Automation
controllers are no longer limited to managing machine behavior – they have
become core components of manufacturing intelligence.
Obsolete controls are an example of what’s known as “technical
debt” in the information technology world becoming exposed in the
operational technology field. When a device (a PLC, for instance) is first
commissioned, it begins to accrue a debt that will eventually need to be paid. The
environment around the device changes, changing the problem set for which the
device was the intended solution. Sometimes an organization will elect to
re-engineer the process to adapt to changing conditions, but the more typical
response is to “tweak” the system and delay the eventual expense and effort
required, increasing the debt payment. Just as with financial debt, this isn’t
necessarily a bad thing – but unmanaged debt usually leads to undesirable consequences.
In operational technology, technical debt has broader reach
than is first apparent. Beyond the cost of the controller, the software to
program/maintain it (plus the training to keep personnel current), and
reprogramming/commissioning costs, there is the surrounding infrastructure to
consider, from I/O wiring to networking to support servers and services (OPC,
revision control, etc.). Modern controls are typically accessible via a
corporate network, even when isolated using technology such as V-LAN or DMZ;
security has become a greater concern. There are also newer industrial
standards which should be included as part of the debt analysis; it isn’t just
the controls hardware which has become obsolete. There are modular programming
standards (ISA-88/IEC 61512), integration standards (ISA-95/IEC 62264), and
automation system security (ISA-99/IEC 62443) which should be incorporated as
part of a complete controls update program. The standards continue to evolve as
well; the ISO Automation Systems and Integration Technical Committee (TC-184)
is working to adopt the ISA/IEC standards as well as adding standards around
robotics and industrial data management.
Obsolete controls programs should cause industrial
organizations to pause and reflect on their operational strategies; what do
they want their production processes to look like five to ten years in the
future? What will their competitor’s processes be like then? Such questions
will have an impact on decisions such as “do we spend the time to re-write the
PLC code for a new processor, or do we just do the minimum work required to fit
the new device into our existing processes?” If those questions are not asked, automation
managers will choose the most direct route to keeping production processes
operational. They will elect to increase the technical debt.
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