OHS Performance Indicators: Leading and Lagging

Why is the number of accidents not enough on its own?

When OHS performance indicators come up, most management meetings discuss a single figure: how many accidents were there this month? This number matters, but it has three weaknesses. First, it describes the past; you find out after the accident has happened. Second, in a small or medium-sized company the numbers are so small that two accidents one year and none the next can be explained by luck. Third, and most dangerous, the easiest way to reduce the number of accidents is to suppress reporting.

That is why we divide OHS indicators into two groups. Lagging indicators (trailing, outcome indicators) measure harm that has occurred. Leading indicators (forward-looking, process indicators) measure how much of the work that prevents accidents is being done. This article proposes a set of indicators that uses both groups together and can be read on a single page at an OHS committee meeting.

The raw data for the indicators is already in your statutory records. Art. 14/1 of Law No. 6331 requires the employer to keep a record of workplace accidents and occupational diseases and to investigate and report incidents with the potential to cause harm even if they do not lead to injury. Training records, medical examination records, periodic inspection reports and findings in the approved logbook are also sources of leading indicators.

Lagging indicators: measuring what has happened

Lagging indicators are indispensable, because what you ultimately want to measure is a reduction in harm. Typical lagging indicators are:

• Number of workplace accidents (with and without incapacity counted separately)
• Working days lost due to workplace accidents
• Diagnosed and suspected occupational diseases
• Number of incidents requiring first aid
• Incidents causing material damage, such as equipment damage or the start of a fire

When using them, set two rules. First, keep the definition fixed: are "lost days" counted from the day after the accident, or is the length of the sick note used? If the definition changes during the year, comparison becomes meaningless. Second, do not exaggerate small numbers by converting them to percentages. Rates divided by hours worked, such as accident frequency and severity rates, require a separate calculation discipline; in a small company the annual trend is more meaningful than a monthly rate chart.

Leading indicators: what changes the outcome

A good leading indicator is directly linked to a preventive measure and is within the company's control. The following items can be measured in almost every workplace:

1. Training completion rate. The proportion of due induction, basic and refresher training delivered on time. For planning, see our article on the annual OHS training plan.
2. Near miss reporting. How many reports came in per month, and how many of them were investigated? For the reporting system, read our article on the near miss reporting system.
3. Action close-out rate and time. The proportion of actions arising from audits, accident investigations, near misses and the risk assessment that are closed by their deadline.
4. Number of site walks. How many of their planned site walks managers carried out.
5. Compliance with the statutory calendar. The proportion of periodic inspections, workplace measurements, periodic medical examinations and drills carried out on time.
6. Safe behaviour observation. The compliance rate observed for critical rules such as PPE use or lockout.

A recommended set of OHS performance indicators

The set below is a starting point for a medium-sized manufacturing company. The target column comes from a legal requirement for indicators tied to a statutory deadline, and from your own decision for the others.

Prepare a definition card for each indicator: its name, formula, what is and is not counted, who collects the data and on which day it is reported. An indicator without a definition card will be calculated differently by different people six months later. A sample card might look like this:

• Indicator: Action close-out rate
• Formula: Number of actions due that month that were closed by the deadline / number of actions due that month
• Counted: Actions arising from audits, accident and near miss investigations, the risk assessment and findings in the approved logbook
• Not counted: Actions whose deadline has been postponed without the postponement being approved by the employer are not counted as closed
• Evidence of closure: A photo, inspection form or signed record; an action without evidence remains open
• Owner and date: The specialist compiles the data on the first working day of each month and presents it at the committee or management meeting

Example: a monthly dashboard in a metalworking plant with 120 workers

The figures are for illustration. Consider the November dashboard of a machining plant in Bursa with 120 workers in the hazardous class:

• Actions: Of the 38 actions due in November, 29 were closed. Close-out rate 29 / 38 = 76%. Six of the 9 actions not closed belong to the same department; this is a finding to discuss with the department manager.
• Training: Of the 18 workers whose refresher training was due to expire, 16 completed the training (89%). Two workers are on sick leave; their training will be scheduled on their return.
• Near misses: 14 reports came in and 11 were investigated. Five of the reports involve forklift and pedestrian encounters; the traffic plan is put on the agenda.
• Periodic inspection: All 12 of the 12 items of equipment due for inspection were inspected (100%).
• Accidents: One accident without incapacity (a cut to the hand). A root cause investigation was carried out and added to the action list.

When this dashboard is read at the committee, the discussion does not end with "there was one accident this month". The concentration of unclosed actions in one department and of near miss reports in forklift traffic shows where the next accident may come from. For how to carry out an accident investigation, see our article on root cause analysis methods.

How are OHS targets set?

OHS targets should be considered together with the annual work plan. The plan lists the work to be done; the target makes the result of that work measurable. To prepare, you can use our article on the annual work plan.

A good target answers the following questions:

• What does it measure? "Improving safety" is not a target; "increasing the proportion of actions closed by their deadline by the end of the year" is a measurable target.
• Who controls it? A target must be something its owner can influence. Instead of the number of accidents, a department head can be given the action close-out rate in their own department.
• When and how will it be reviewed? In workplaces with 50 or more workers, the OHS committee is the natural place for this review; for how the committee works, see our article on the OHS committee.

"Zero accidents" can be used as a statement of values, but when set as the only measurable target it carries the risk of suppressing reporting. In companies using ISO 45001, the monitoring and measurement requirement is fed by these indicators; for the structure of the standard, see our article what is ISO 45001.

Common mistakes that distort indicators

• Accident-free days award. When a reward is tied to the number of accidents, a worker may not report minor accidents so as not to cost their team the reward. If there is a reward, tie it to reporting and improvement suggestions.
• Too many indicators. A dashboard with twenty indicators will not be read. Between six and ten indicators are enough.
• Numbers only. If none of a hundred near miss reports is investigated, the number is misleading; put the investigation rate next to the number of reports.
• Data of unclear origin. An indicator's data should come from statutory records: training records, medical examination records, inspection reports.
• Turning indicators into a punishment tool. Indicators are used not to compare departments but to see where support is needed. For how this approach relates to culture, see our article on OHS culture.

The easiest way to track indicators tied to the statutory calendar is to keep the dates in one place; the OHS calendar can be used for this. For companies in Bursa and the surrounding provinces, setting up the indicator set and monthly reporting can be planned under our OHS specialist service.

Frequently Asked Questions

What is the difference between leading and lagging indicators?

A lagging indicator measures harm that has occurred: the number of accidents, lost days, occupational diseases. A leading indicator measures whether the work that prevents harm is being done: training completion, near miss reporting, action close-out, site walks.

How many OHS KPIs should we use?

Between six and ten indicators are enough for most companies. The definition, formula, data source and owner of each should be written down.

If near miss reports increase, is that a bad sign?

Usually not. An increase in reporting often shows that workers trust the system. What matters is that reports are investigated and actions are closed.

Who sets OHS targets?

The employer sets and approves them; the specialist and physician propose them together with the annual work plan. In workplaces with a committee, the review of targets can be put on the committee agenda.