Risk Assessment Made Practical: 5x5 Matrix Examples for Site Supervisors
A practical risk assessment starts with the job, the people exposed and the controls that actually work. A 5×5 matrix helps prioritise the findings by multiplying likelihood by severity; it does not make the workplace safe on its own.
This guide gives site supervisors a worked scoring method, a complete 5×5 table and three illustrative workplace examples. Use it to improve the conversation before work starts, then record who will implement each control and how you will check it.
Scope: The scales, action bands and scenarios below are Safety Institute Pakistan editorial examples, not a prescribed NEBOSH, ISO or Pakistani regulatory matrix. Use your organisation’s approved method and applicable local requirements. The examples are teaching exercises, not completed assessments for a real site.
Key takeaways
Describe the hazardous event and possible harm before choosing numbers.
Use the same likelihood and severity definitions throughout an assessment.
Separate existing controls from proposed improvements.
Keep a proposed residual rating provisional until controls are installed and verified.
A numerical score cannot override a missing critical control, a permit requirement or an applicable legal duty.
What a supervisor’s risk assessment needs to answer
For each activity, ask: what could go wrong, who could be exposed, what prevents it now and what still needs to change? The UK Health and Safety Executive’s risk management guidance organises the process around identifying hazards, assessing risks, controlling them, recording findings and reviewing controls. Involve workers and include maintenance, cleaning and other non-routine tasks.
Keep the wording specific. “Vehicle hazard” gives the next shift little to act on. “A pedestrian could be struck by a reversing delivery vehicle at the shared unloading entrance” identifies an event, a location and an exposed group.
A useful assessment has enough detail for someone else to recognise the conditions you assessed. Record the work area, task boundaries, equipment, shifts and people consulted. If the delivery route changes tomorrow, the supervisor should be able to see that the assessment needs another look.
How a 5×5 risk matrix works
Risk priority score = likelihood (L) × severity (S). With each factor rated from 1 to 5, the resulting score ranges from 1 to 25. These are ranked categories, not measured probabilities. A score of 20 does not mean an accident has a 20% chance of occurring, and it is not proof of twice the risk represented by a score of 10.
The value comes from consistent reasoning. Two assessors should be able to explain why they chose their categories. If they disagree, examine exposure, equipment condition and control reliability before averaging numbers or choosing the more convenient score.
Example likelihood scale
Apply these descriptions to the stated task and exposure conditions, considering the controls already present. This example does not assign annual frequencies; an organisation that uses frequency-based definitions should apply those approved definitions instead.
| L | Description | Reasoning prompt |
|---|---|---|
1 | Rare | Harm would require an exceptional combination of circumstances; strong controls are verified. |
2 | Unlikely | Harm is credible, but not expected under the defined conditions and reliable controls. |
3 | Possible | Harm could occur; exposure or weaknesses make the event reasonably foreseeable. |
4 | Likely | Repeated exposure and weak or unreliable controls make harm likely. |
5 | Almost certain | The event is expected under the conditions being assessed unless something changes. |
Example severity scale
Choose a credible consequence of the event, not an implausible worst case and not the outcome you hope for. Assessors must agree on the scenario before using the scale.
| S | Description | Illustrative consequence |
|---|---|---|
1 | Slight | Minor, short-lived injury requiring first aid only. |
2 | Minor | Reversible injury or illness requiring medical treatment. |
3 | Serious | Significant injury or illness with prolonged recovery or absence. |
4 | Major | Permanent disabling injury or severe irreversible ill health. |
5 | Catastrophic | Fatal injury or fatal occupational illness, potentially affecting more than one person. |
Where several people could be harmed, record the potential number exposed as well as the consequence category. A single product score can hide important differences between scenarios.
The complete 5×5 scoring table
| Likelihood ↓ / Severity → | 1 Slight | 2 Minor | 3 Serious | 4 Major | 5 Catastrophic |
|---|---|---|---|---|---|
5 Almost certain | 5 | 10 | 15 | 20 | 25 |
4 Likely | 4 | 8 | 12 | 16 | 20 |
3 Possible | 3 | 6 | 9 | 12 | 15 |
2 Unlikely | 2 | 4 | 6 | 8 | 10 |
1 Rare | 1 | 2 | 3 | 4 | 5 |
Example action bands: agree them before scoring
| Score | Example band | Example management response |
|---|---|---|
1–4 | Low | Maintain and check controls; confirm all task requirements remain satisfied. |
5–9 | Moderate | Review further reduction options, assign actions and obtain the approval required by site rules. |
10–16 | High | Do not start or continue the affected task until additional controls and reassessment meet site requirements. |
17–25 | Very high | Stop the affected activity, protect people from exposure and escalate for redesign and reassessment. |
These bands are illustrative, not universal acceptance limits. Add an escalation rule for fatality-potential scenarios: even a low-likelihood fatal event needs competent scrutiny and verification of critical controls. In this example, 1 × 5 = 5 falls into “moderate”; that label must never turn a missing vehicle barrier or fall-prevention measure into an acceptable omission.
Loughborough University’s assessment guidance provides a useful comparison of a numerical matrix in practice and explains that scoring depends on competent judgement. Its institutional method is not the SIP example above.
Current risk, inherent risk and residual risk
Forms use these terms differently. Write the basis next to the rating so the reader does not have to guess.
Inherent risk: a defined hypothetical assessment without specified controls. State exactly which controls are excluded if your system requires this rating.
Current risk: the risk with controls that are actually in place and working at the time of assessment.
Target residual risk: the expected rating if proposed additional controls work as intended.
Verified residual risk: the reassessed position after those controls have been implemented and checked.
A purchase order for a barrier is not a barrier. Keep the current rating visible while the action remains open. If temporary arrangements are necessary, assess those arrangements separately rather than borrowing the rating intended for the permanent solution.
Choose controls before trying to reduce the score
The NIOSH hierarchy of controls orders the options as elimination, substitution, engineering controls, administrative controls and personal protective equipment. Removing the hazard or controlling exposure through design generally depends less on continual individual action than instructions and PPE.
For a supervisor reviewing an unloading task, that means asking whether deliveries can be separated from pedestrian activity before adding another warning sign. For a handling task, ask whether the load can be delivered to its point of use before repeating a lifting briefing. Check that any changed method does not introduce a different uncontrolled hazard.
Worked example 1: vehicles at a shared unloading entrance
Illustrative situation: pedestrians and reversing deliveries share a warehouse entrance. Faded floor markings and a high-visibility clothing rule are the existing precautions. Workers cross the route repeatedly during deliveries.
The event is a pedestrian being struck or crushed. For this teaching example, repeated exposure and weak separation support L4; a credible fatal outcome supports S5. Current score: 4 × 5 = 20, very high. Stop the affected shared-use arrangement and keep people clear while a controlled alternative is developed.
Possible improvements include changing the delivery layout to reduce reversing, physically separating pedestrian routes and controlling necessary crossing points. The UK HSE’s workplace transport assessment guidance supports considering layout and vehicle measures rather than relying on instructions alone.
| Action | Example owner and timing | Verification before closing |
|---|---|---|
Establish a protected pedestrian route and prevent uncontrolled entry into the unloading zone. | Logistics manager, before shared operations restart. | Walk the complete route; inspect barriers, access points and visibility. |
Brief workers and visiting drivers on the revised arrangement. | Shift supervisor, before the first delivery under the new system. | Ask users to explain the route and observe an actual delivery. |
Check the arrangement during busy and low-light periods. | Site manager, during initial operation and scheduled inspections. | Record observations, defects and corrective actions. |
A proposed L1 × S5 = 5 is only a target for this scenario, conditional on strong, verified separation. The possible consequence remains fatal. If the barrier can be bypassed or deliveries still cross the pedestrian route without effective control, the likelihood needs reconsideration. This example does not establish a safe design for your site.
Worked example 2: an obstructed pedestrian walkway
Illustrative situation: packaging and a temporary cable obstruct a level internal walkway. Staff repeatedly step around them. The assessed event is a trip with a credible serious injury: L3 × S3 = 9, moderate.
Remove the packaging and reroute the cable away from the walkway using an appropriate installation. Assign a clear housekeeping responsibility and inspect the route at handover. After checking the route under normal operating conditions, a supervisor might justify L1 × S3 = 3 for the defined scenario.
Do not automatically score a trip near an open edge the same way. The location changes the credible consequence. Assess a possible fall separately and address the edge protection before work proceeds.
Worked example 3: carrying materials along an awkward route
Illustrative situation: workers repeatedly carry bulky cartons from a store to a work area along a route with turns and limited space. The existing arrangement relies on workers asking for help. For a defined musculoskeletal injury scenario, the teaching rating is L4 × S3 = 12, high.
Consider delivering materials closer to use, reducing package size and selecting a suitable handling aid for the load and route. Evaluate the new arrangement for stability, gradients, trapping and pedestrian conflict. A manual handling specialist may be needed where the task is complex.
If the redesigned task removes most carrying and the trial demonstrates a reliable improvement, a provisional target of L2 × S3 = 6 may be reasonable for this example. Verify it through observation and worker feedback. Do not infer a universal safe lifting weight or a medically safe exposure from that number.
A simple risk assessment record supervisors can use
The HSE’s template and examples emphasise recording exposed people, existing precautions, further actions, responsibility and timing. They also warn against copying an example without examining the real workplace.
For a matrix-based record, add the scoring basis and verification fields:
| Field | What to record |
|---|---|
Task and scope | Activity, location, conditions, equipment and people consulted. |
Hazardous event and harm | What could happen, to whom, and with what credible consequence. |
Existing controls | Precautions observed and evidence that they function. |
Current rating | L, S, product and the explanation behind each choice. |
Additional actions | Specific improvement, named owner and completion deadline. |
Target residual rating | Expected position, clearly conditional on implementation. |
Verification and approval | Who checked the controls, when, with what evidence, and the resulting rating. |
Review triggers | Changes or failures that require reassessment, plus the scheduled review date. |
Common scoring mistakes and how to correct them
Choosing the desired colour first. Write the event, consequence and evidence before selecting L and S.
Reducing severity because training was delivered. Ask whether the control changes the possible injury or primarily changes the likelihood. Keep severity unchanged where the consequence remains credible.
Counting proposed controls as existing. Record a target rating separately and retain the current rating until verification.
Assuming no accident means no risk. Check exposure and control condition; absence of a recorded injury is not evidence that a barrier works.
Writing “take care” as the action. Specify the physical or procedural change, the owner and the check that will demonstrate completion.
Using the matrix for everything. Chemical exposure, occupational noise, lifting operations and other specialist hazards may require additional methods and competent input.
Brief the team and check the work
Before starting, ask workers to describe the main event you are preventing, the controls they rely on and the circumstances that require stopping. Use language they understand and demonstrate the arrangement at the work area. A signature alone does not show understanding.
During the task, compare the actual conditions with the assessment. The HSE recommends reviewing controls when they may no longer be effective, when work changes or when incidents, near misses or worker concerns reveal problems. Update the record after the review.
A dynamic check is useful when circumstances change, but it should not be used to improvise a replacement for a specialist assessment or required work authorisation. If the team cannot maintain the agreed controls, stop the affected task and escalate through the site process.
Frequently asked questions
This guide does not establish a legal requirement to use one. Use the assessment method required for your workplace and activity. A matrix is one way to prioritise findings; specialist assessment requirements and local duties still need separate attention.
There is no universal answer in this example. Your organisation must define approval rules and required controls. A score does not grant permission to ignore a safeguard or a legal requirement.
This 1-to-5 model has no zero category. If the hazardous activity is eliminated, record that change explicitly rather than forcing an artificial zero into the table. Check for risks introduced by the replacement activity.
No. An assessment identifies hazards and controls; a permit system authorises and coordinates defined work under site rules. Where a permit is required, both processes need to agree on the precautions.
Use them to understand the reasoning, not as a submission template. Follow the current official assessment instructions and assess your own suitable workplace. Our NEBOSH IGC study guide explains how preparation and practical observation fit together.
Your final supervisor check
Can the team point to the hazard and explain the harm?
Are the controls present, functional and suitable for today’s conditions?
Do the scores have a written reason?
Does every open action have an owner and a deadline?
Has someone verified the controls before accepting the residual rating?
Does everyone know when to stop and request reassessment?
A useful risk assessment changes what happens at the workface. Finish with a control someone can inspect, an action someone owns and a decision the next shift can understand.
Sources and further reading
Sources checked 4 November 2026. International guidance is used for the assessment principles; UK legal thresholds are not presented as Pakistani requirements.
Categories :
