How Precursor Events Can Prevent Incidents - Part 1
A term that has entered the vernacular of many safety professionals in recent years is “precursor events”. But what are they, and why are they important? And - most importantly - how can they help improve your organization’s safety?
Traditional Safety Methods: Lagging Indicators
Historically, most safety processes and changes have come about as a result of lagging indicators, meaning events or outcomes that have already occurred. In the safety world, lagging indicators are established by calculating injury rates - for example, the number of falls recorded on a job site in the past year is a lagging indicator of the safety issue that is causing the falls.
Based on the fact that lagging indicators review events that have already occurred, the safety measures established as a result of them are inherently reactive. Lagging indicators can only tell you about hazard or failure in a safety program after something has occurred; they measure the end results of safety policies and procedures, and inform future changes.
One concern around lagging indicators is that they don’t pinpoint where the safety improvement is needed, only if it is needed, and how badly. And since that specific “why” is not there, the resulting corrective actions can end up being broad and generalized, potentially hampering other activities or not even addressing the actual cause. Also, because each change that is made as a result of a lagging indicator will then also be measured after the fact, this can result in a slow process of change that impacts employees, resource allocation, and productivity.
Using Precursor Events: Leading Indicators
Leading indicators are events or observable variables that reliably predict or precede other events before they occur. For example, an electrical near miss can be a precursor to an electrical incident, or someone operating heavy machinery while tired can be a precursor to a collision or other incident. Where lagging indicators are reactive, leading indicators are proactive. One or more leading indicators will make up a precursor event.
There are several different types of leading indicators that can make up a precursor event:
Observation-based indicators: these are indicators that can be tracked by assessing behavior and hazardous conditions to determine risk
Operations-based indicators: this type of indicator can be attributed to an organization's infrastructure and process, and includes risk assessments, risk mitigation through the hierarchy of hazard control, and safety training
Systems-based indicators: are indications that primarily pertain to management factors, such as organization culture, psyche, and design
As leading indicators are predictive, precursor events can be used to prevent incidents and understand your safety program before an issue occurs, as well as measure the effectiveness of a safety program, and reveal potential problems.
The timing, magnitude, and duration of future events can be forecast using leading indicators, allowing the organization to adjust the reaction appropriately to prevent or mitigate the impact of the safety concern. Precursor events can also help reduce costs associated with incidents, improve overall organizational performance and productivity, and increase worker participation in safety.
Improving Safety: Using Both Lagging and Leading Indicators
Both leading and lagging indicators have their benefits and their drawbacks. Leading indicators, and the precursor events they make up, are dynamic and can help prevent incidents before they happen, but they are difficult to measure and harder to quantify. Lagging indicators are much easier to measure, but can be harder to change and do not prevent the incidents that they are measuring.
Safety improvements are most effective when they include both precursor events (and leading indicators) and lagging indicators. Leading indicators and precursor events are most valuable when used to drive change, whereas lagging indicators are useful to measure the effectiveness of the safety program. This allows for the resulting safety processes to be both proactive (using precursor events) and reactive (using lagging indicators).
Some research suggests using fewer than five leading indicators is most effective. Organizations tracking more than five leading indicators end up having higher incident rates because tracking so many can detract focus or seem daunting or unmanageable.
In the next post we will explore how to successfully implement the use of precursor events in your organization’s workplace safety program.