One mine, before and after
At an underground longwall coal mine in New South Wales, daily run-of-mine output swung widely under a conventional balanced-capacity approach. The before-and-after chart shows an average initially 32% below demonstrated capability, narrowing to 16% in the first phase of flow-based operation.
In August 2023, coinciding with the start-up of a new Longwall, the mine made the coal handling and preparation plant (CHPP) its managed constraint. It paced production to what the CHPP could process and used the ROM stockpile as a buffer with clear triggers.
Annual production rose from a 2.4 million tonne average over 2018–2023 to 3.2 million tonnes in 2024: a 33% increase, with no new capital and no additional people. The annual result and the chart’s first-phase comparison describe different periods.
Source: Lourens (2026), “Breaching the Mining Fatalities Plateau: Financial Pressure, Operational Instability, and the Case for Flow-Based Safety”, Journal of Industrial Safety, 3, 245–255
Why the scatter matters for safety
Repeated production shortfalls can create catch-up pressure elsewhere in the chain. The proposed mechanism is that this pressure consumes time and attention needed for planning, maintenance and critical-control verification. A steadier operation may reduce that pressure at its source.
The pattern we see again and again
Across more than 90 interventions using this methodology since 2000, on three continents, operators have repeatedly reported safety improvements alongside higher and more stable production. This is practitioner evidence that warrants formal testing. It does not establish that flow-based production causes fewer serious injuries or fatalities.
STOP-START FLOW
Unstable production, output below target and repeated recovery efforts.
ALIGNED FLOW
The constraint is identified and protected with buffers and protective capacity. The illustrative pattern shows output gains of 10–20% in the early months.
SUPERFLOW
A daily flow room supports coordination across departments. The illustrative pattern shows more stable production and output 20–40% above the starting level.
The time scale and percentage ranges are indicative practitioner observations, not pooled statistical results or guaranteed outcomes.
What people at the mine said about safety
The change was made to how production was run. The paper records observations from management, the workforce and the CHPP manager. These are different perspectives within the same operation, rather than independent verification of safety outcomes.
MANAGEMENT
“Many of the management team believe that the excellent safety performance is the result of the new way of working.”
Management team · client-feedback compilation, 2024
THE WORKFORCE
“For the first time, [we] feel management and workers are working together.”
Mining and Energy Union representative, 2024
“It’s great coming to work, everyone’s more relaxed, and we’re working together.”
Underground crew member, 2024
Source: Lourens (2026), “Breaching the Mining Fatalities Plateau: Financial Pressure, Operational Instability, and the Case for Flow-Based Safety”, Journal of Industrial Safety, 3, 245–255.
The manager responsible for the constraint
“It’s probably too early to claim credit for safety results, but the feedback from crews and staff has been clear—the Flow Room has changed how we work.”
CHPP Manager · 18 March 2025 · excerpt reproduced in the paper
The manager described clearer priorities over the next 48 hours, calmer planning, fewer rushed decisions and more controlled execution.
During poor roof conditions on the longwall, forward projections of ROM buffer levels showed the developing problem days ahead. Dozer resourcing, maintenance windows and CHPP feed were re-planned across departments before the longwall needed to be pushed. His account describes a coordinated response without the usual panic.
The Operations Manager’s experience was recorded in the same client-feedback compilation:
“Since September [2023] [the Operations Manager] says he can focus on discharging his mandated responsibilities - there is no more firefighting.”
Client-feedback compilation, 2024, reproduced in the paper
Lourens (2026), “Breaching the Mining Fatalities Plateau: Financial Pressure, Operational Instability, and the Case for Flow-Based Safety”, Journal of Industrial Safety, 3, 245–255.
Other observations and the limits of the evidence
OTHER PRACTITIONER OBSERVATIONS
The South African bord-and-pillar coal case reported 70 consecutive incident-free days during record production.
At the 2015 TOCICO World Conference, Arrie van Niekerk described a Witwatersrand gold shaft whose monthly stoping output rose from 9500 to 16 000 square metres."They got all the rewards for that group. They walked away every single quarter with all the safety rewards, all the productivity awards, everything, all the profitability awards for that whole group, to the envy of their colleagues." Watch the video here.
Similarly, a open cut iron ore miner, one of three in its group, won the group's prizes for best grade and process control, best production improvement and best safety performance. Internal Laureus awards, 2014
Senior mine executives have said "the TOC Flow implementation should really be marketed as a safety intervention and not a productivity intervention." As reported by a former Goldratt South Africa executive, June 2024
"The TOC implementation delivered not only productivity but obvious and visible safety improvements." Consultant to a Tier 1 narrow-reef mine, July 2026
WHAT STILL NEEDS TESTING
The link between operational stability and control effectiveness is a hypothesis, and one mine is not enough to test it. Near misses are a poor measure on their own. Under production pressure they tend to go unreported, while a more stable operation often reports more because people have the time to do so, so a site can look worse on paper as it improves. The outcomes that matter, serious injuries and fatalities, are too rare at any single mine to show a real effect. A credible test needs pooled data from many mines over several years, comparing measured production instability with serious injury and fatality outcomes. Work at individual sites can still show whether critical controls slip during periods of heavy replanning or disruption. Stratflow would like to hear from operators, industry bodies, researchers and regulators who could help build that evidence.
A 10-minute check with data you already have
Use this as a starting point for investigating production instability.
1. Take 12 months of daily run-of-mine tonnes on a consistent reporting basis.
2. Identify the three best daily results. Check that it is a valid operating result, and use their average as the best daily output.
3. Calculate average daily output over the same period.
4. Express the difference as a percentage of the best daily result.
Gap (%) = (best daily output − average daily output) ÷ best daily output × 100
The paper uses the best days as a practical estimate of demonstrated capability. A gap of 25% or more is a practitioner-derived heuristic which we have found to indicate a balanced-capacity chain with moving bottlenecks.
Source: Lourens (2026), Figure 6 and diagnostic discussion.
Talk through what your numbers show
If you would like to discuss the evidence, explore a research collaboration or look at your operation’s production pattern, I’m happy to have that conversation.
Hendrik Lourens, FAusIMM
CEO, Stratflow Australia
Read the supporting paper: Lourens (2026), “Breaching the Mining Fatalities Plateau: Financial Pressure, Operational Instability, and the Case for Flow-Based Safety”, Journal of Industrial Safety, 3, 245–255.
DOI: 10.1016/j.jinse.2026.06.002