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  • Writer's pictureAdvizint Team

Ensuring Equipment Safety: A Vital Step in Control System Upgrades

industrial workers using PLC automation via HMI

The rapid evolution of manufacturing technology has left many companies grappling with outdated control systems. The challenge of finding scarce replacement parts only amplifies the urgency to upgrade. Yet, while the decision to modernize control systems seems straightforward, there's an aspect that often slips through the cracks: the safety systems. Let's delve into the importance of enhancing equipment safety during control system upgrades and introduce the foundational steps in the safety evaluation process.

The Urgency of Control System Upgrades

When control systems become obsolete, manufacturers confront significant risks that threaten their entire production process. A malfunctioning component could lead to prolonged downtime, impeding their ability to meet market demands. This ripple effect can result in missed business ventures and significant revenue loss. Upgrading control systems is, thus, not just about efficiency but also about sustaining competitiveness.

The Often Overlooked Aspect: Safety System Upgrades

A malfunctioning control system is immediately evident, but an outdated safety system's consequences can lie dormant until a catastrophic incident. The repercussions? Potential injuries or even fatalities. Over the past decade, advancements in assessing employee risk and evaluating the reliability of safety systems have been remarkable. It's imperative to consider that an obsolete control system usually means the associated safety system may be equally outdated.

Safety Evaluation Process Steps

To comprehensively address equipment safety during control system upgrades, a meticulous safety evaluation process is non-negotiable. Typically, this involves:

  1. Evaluation of Hazards: Scrutinize equipment, processes, and the work environment to pinpoint potential risks.

  2. Initial Risk Estimate: Once hazards are identified, deduce the initial risk level. This encompasses analyzing potential injury severity, frequency of exposure to hazards, and the effectiveness of current safety protocols.

  3. Risk Reduction Measures: Strategize and enforce measures to alleviate identified hazards. This could range from new safety protocols to an overhaul of safety equipment or even amending processes.

  4. Final Risk Estimate: Post-implementation of risk reduction strategies, re-assess the risk levels to ensure they are minimized and within acceptable thresholds.

Engaging a multidisciplinary team, including safety engineers, equipment operators, and maintenance staff, can foster a more holistic evaluation and risk mitigation approach.

Risk Assessment

Central to the safety evaluation process is the risk assessment phase. It prioritizes safety interventions by assessing hazards and their associated risk levels. Factors such as injury severity, frequency of exposure, and chances of avoidance are pivotal.




Injury Severity



*Normally non-reversible; likely will not return to the same job after recovery from incident: fatality; limb amputation; long-term disability; chronic illness.

If any of the above are applicable, the rating is SERIOUS



​*Normally reversible; likely will return to the same job after recovery from incident: severe laceration; short hospitalization; short-term disability; loss time (multi-day); fingertip amputation (not thumb).

​If any of the above are applicable, the rating is MODERATE



*First Aid; no recovery required before returning to job: bruising; small cuts; no loss time (multi-day); does not require attention by a medical doctor.

If any of the above are applicable, the rating is MINOR




​**Exposure to hazard(s) is effectively mitigated by design

**Use of guards prevents exposure or access to the hazard(s). If an interlock guard is used, the third bullet point must be met.

​**If functional safety is used as a risk reduction measure, the functional safety performance (PL) meets or exceeds the required functional safety performance (PLr).

If any of the above are applicable, the rating is PREVENTED



​*Typically more than once per hour

*Frequent or multiple short duration

​If any of the above are applicable, the rating is HIGH



​*Durations/situations that could lead to task creep and do not include teach

*Typically less than or once per day or shift

*Occasional short durations

If any of the above are applicable, the rating is LOW


​Not Possible


​*Insufficient clearance to move out of the way

**Equipment operating at hazardous speed without safety-rated reduced speed control

*The equipment layout causes the operator to be trapped, with the escape route toward the hazard

*Safeguarding is not expected to offer protection from the process hazard (e.g. explosion or eruption hazard)

If any of the above are applicable, the rating is NOT POSSIBLE

​Not Likely


*Insufficient clearance to move out of the way

**Equipment operating at hazardous speed with safety-rated reduced speed control

*Obstructed path to move to safe area

*Hazard is moving faster than reduced speed (250 mm/sec)

*Inadequate warning/reaction time

*Might not perceive the hazard exists

If any of the above are applicable, the rating is NOT LIKELY



​*Sufficient clearance to move out of the way

*Hazard is incapable of moving greater than reduced speed (250 mm/sec)

*Positioned in a safe location away from the hazard

If any of the above are applicable, the rating is LIKELY

Additional Steps

This overview touches upon the preliminary steps of the safety evaluation process. However, a comprehensive approach involves additional intricate details, which we'll cover in future posts.

In Summation

Overlooking safety systems during a control system upgrade can have dire consequences. These interconnected systems require simultaneous upgrades to ensure both employee and equipment safety. Through a systematic safety evaluation process and a steadfast commitment to risk reduction, manufacturers can ensure that their upgrades are both safe and successful. Stay engaged for subsequent insights into this pivotal facet of equipment safety.


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