Short answer. HSG65's Plan-Do-Check-Act cycle only works as a cycle. Most organisations plan well, implement partially, check rarely, and act on findings almost never, which leaves a safety system that looks compliant on paper but does not actually manage risk day to day.
Plan: the strategic bit
The Plan phase is where the health and safety approach is set. It covers more than writing a policy.
Policy and objectives. A documented commitment to health and safety with specific aims, not vague aspiration. "Reduce incidents by a stated amount" or "improve hazard reporting through an accessible reporting system" gives something to measure against later.
Risk assessment. A systematic identification of hazards specific to the operation and the site, not a generic template.
Organisation and resources. Who is responsible for what, what training people need, what budget is allocated, and what happens when someone spots a hazard.
Hazard control strategy. How risks will be controlled: eliminated where possible, or reduced through engineering controls, administrative controls and personal protective equipment.
Many organisations stop here. A policy, a risk assessment and an organisational chart get produced, and then little changes on the ground.
Do: where implementation falls apart
"Do" means implementing the controls that were planned, and it is where most systems fail, because the gap between planning and doing takes ongoing attention rather than a single push.
Identifying that forklift operators need certification is the easy part. Arranging the training, releasing people from shifts, and documenting that it happened requires continuous effort. Identifying that a work area needs better ventilation is easy; arranging surveys, budgeting, scheduling installation and testing it afterwards takes months, and it is tempting to defer.
Implementation commonly stalls for a few reasons: it gets treated as a one-off rather than something that needs maintaining as people, equipment and processes change; no budget or protected time is set aside, so it becomes inconsistent; procedures are handed down without input from the people who do the work, so they don't fit and get worked around; and induction training is treated as sufficient on its own, with no refresher training as people join, move on or forget.
Check: the monitoring bit that gets skipped
"Check" verifies that what is happening on the ground matches the plan. Without it, an organisation is relying on hope that procedures are followed and that control measures work.
Good checking covers four things. Inspection and audit: regular walkthroughs to see whether fire doors are closed, PPE is worn, and the chemical store is locked. Performance monitoring: incident numbers, near-miss reports, training completion and maintenance records, used carefully rather than reduced to a single headline figure. System audits: whether hazards have changed since the last risk assessment, and whether control measures are still appropriate given changes in the business. Incident investigation: establishing what happened and why when something goes wrong, rather than finding an individual to blame and moving on.
The checking phase is what tells an organisation whether its plan is actually working.
Act: the improvement step that rarely happens
"Act" takes the results of checking and uses them to improve the system, addressing the root cause rather than the symptom.
If audits show fire doors are regularly propped open, the useful response is to find out why, a ventilation problem, a bottleneck, a noisy closer, rather than simply telling people again not to do it. If investigations show a procedure is being worked around because it doesn't suit the actual job, the procedure needs updating. If incidents show a tolerated hazard is riskier than assumed, the control measures need reassessing.
Act tends to fail for practical reasons: it means admitting the original plan was imperfect, which some people take personally; it usually costs money or causes disruption, so "we'll try harder to follow the procedure" feels easier than fixing the procedure; and without it, checking starts to feel pointless, which discourages people from reporting problems at all.
Why most organisations get stuck
In practice, Plan is usually done: a policy is written, a risk assessment completed, procedures documented, and the system looks compliant. Do happens partially: initial implementation and training take place but fade over time. Check is minimal: perhaps an annual audit, with incident reports filed rather than properly investigated. Act rarely happens at all: the system stays the same year after year, even as the business changes around it.
The result is a static system that demonstrates compliance at a point in time rather than one that manages safety as an ongoing process.
Making it work
Treat the four phases as a cycle rather than a line: plan on a set schedule, do continuously, check on a set schedule too, and act on what checking finds. Make checking systematic rather than relying on spot checks, with audits scheduled, responsibility assigned, and results recorded. Investigate properly rather than superficially, and treat what an audit finds as a system question ("why did the system allow this") rather than an individual one ("why did this person get it wrong").
Act on findings promptly rather than after months of deliberation, and put budget, time and people against it: audits do not happen if nobody has time to run them, and improvements do not happen without resource behind them. Finally, be explicit with staff that finding a problem through checking is the system working, not a failure to hide, since that is what keeps people reporting issues in the first place.
The bottom line
The organisations that manage health and safety well are not the ones with the most polished policy documents. They are the ones that complete the whole cycle: plan, do it consistently, check whether it is working, and act on what they learn. A safety system that has looked the same for years, existing mainly to demonstrate compliance, is usually stuck at Plan. Moving it on means committing to Do, Check and Act as well.
York Green's health and safety consultancy service works through the full HSG65 cycle, from the initial policy and risk assessment through to the audits and reviews that keep the system live. For the source guidance, see HSE's Managing for health and safety (HSG65).