Secret life of plants

If asked, most plant managers would say hand on heart that they were aware of every activity on the shop floor. But many of them rely on real-time information provided by their plant monitoring software.

So what if these real-time reports do not actually paint an accurate picture?

Accidents and plant downtime occur when either people or equipment fail, but as a plant manager you learn from day one that zero risk is unattainable and unrealistic.

Risk and contingency, as well as events that are partially hidden to the vigilance of the operator, are all part of the secret life of your plant.

Wayne Matthews

A healthy risk-based approach, however, can save time and reduce the scale of existing vulnerabilities, making contingency a little more manageable.

A risk-based approach to plant management would typically include five key steps.

The first is the performance of an initial risk assessment to determine system impact.

Next, plant owners need to identify the functions impacting staff safety, product quality and data integrity by performing functional risk assessments and identifying controls.

The penultimate stage is to implement and verify those controls, and the final step is to review risks and monitor.

This can be achieved by implementing a function monitoring solution, and plant safety teams are also tasked with conducting hazard and operability studies (HAZOP) and creating layer of protection analysis (LOPA) safety plans.

A hazard and operability study is a structured and systematic examination of a planned or existing process or operation, which identifies and evaluates the problems that might represent risks to personnel or equipment, or prevent efficient operation.

The HAZOP technique uses software to record the deviation and consequence within plant operations.

LOPA evaluates risks by orders of magnitude of selected accident scenarios and builds on information developed in qualitative hazard evaluation.

The objective of implementing functional safety systems is alleviating the unacceptable risk of physical injury or of damage to the health of people through damage to property or to the environment.

It is also a key requirement of complying with HAZOP and LOPA conditions.

Most sophisticated facilities collect immense amounts of safety data using a variety of systems.

Collating that data and extracting the essential information needed for the safe running of the plant can be challenging at the best of times.

However, not having access to rationally compiled safety key performance indicators (KPIs) and reports makes it more difficult to understand the current performance of a facility versus design expectations.

Functional safety monitoring

Plant managers need a reliable function monitoring solution that is able to collect, process and present safety data. This enables monitoring and analysis of safety KPIs such as Safety Instrumented Functions (SIF) activations, and Independent Layers of Protection (ILPs), initiating causes and overrides.

Functional safety is the part of the overall safety of a system or piece of equipment that depends on the equipment operating correctly in response to inputs, including the safe management of likely operator errors, hardware failures and environmental changes. Safety functions prevent explosions and environmental damage.

For instance, in the case of an oil refinery located near a housing estate, understanding the environment and potential hazards is literally a matter of life and death.

The virtuous circle

In case of emergency - such as plant shutdown - time is of the essence. For instance, safety monitoring using historian software can save time, because data can be quickly interrogated to find where the fault lies.

This also translates to higher plant availability and lower levels of operator error.

Decisions can thus be made in an informed manner, after assessing all of the variables. The starting point of the virtuous circle theory is the maintenance and operations element of the business.

Here, safety function monitoring collects activation data from the safety system as well as other devices critical to safety function performance such as Programmable Logic Controllers (PLC) and Distributed Control Systems (DCS).

Moreover, it also collects process data and partial stroke test data to compare baseline performance. This enables accurate reporting on device failure rates and can help pinpoint the devices or systems not performing as expected.

After that, the next link in this circle is the key role safety monitoring plays in validating safety activations with successful performance, which helps optimise test scheduling.

This allows plant supervisors to use functional safety assessment reports to make sure they comply with HSE regulations.

The principal benefit of safety monitoring is that it is configured with each individual plant’s operational risk assessment expectations and design in mind.

Risk and contingency, as well as events that are partially hidden to the vigilance of the operator, are all part of the secret life of your plant.