Matrices Used in Safety Management
Near Hits
The Near Hit document is designed to give field operations the ability to convey field, tool and equipment conditions as well as personnel actions to the office. The document does not fix, control or protect workers from hazardous conditions or situations on the site. It is, however, a tool that can be used by both the field staff as well as the office to help track and identify areas of concern, not just for that particular project but areas of concern for the entire Branch. Depending on the scope of work, it may have the potential to affect the entire company.
To initiate this process, the field staff must first identify the near hit condition; this is the single most important aspect of the Near Hit Program. Next is to communicate their findings to the field leadership to enact the Near Hit Protocol. Utilizing the Matrix, the field leadership along with the crew can determine an actionable plan which could either be to mitigate the hazard or at a minimum determine that no hazard exists and continue to work. The Matrix Protocol can be found using the Matrix Flow Chart on the following page. This flow chart takes the user through the necessary steps to ensure proper use of the Near Hit form. The end result is to ensure safe working conditions for employees, protection of company property and the safety of anyone else potentially exposed to hazardous conditions or actions.
Matrices Used in Safety Management
Identify Hazard
Communicate to Field Leadership
5
4
4/5
3
Send form to office for review w/ in 24 hours
1/2
Send form to office by weeks end for possible review
Fill out Near Hit form Share w/ Crew Matrix Evaluation Stop Work Share w/ Crew Develop Abatement Plan
Contact Sup/PM for Abatement Approval
Abate Hazard Finish filling out Near Hit form
Abate if Feasible
Matrices Used in Safety Management
Near Hit Reporting and Recording
Once the Near Hit form is turned into the Project Manager (PM), the form should be evaluated to ensure that the Matrix was properly used. The PM then must decide if a Near Hit Incident Review should be performed. This review could include the Division Manager (DM), PM, Project Engineer (PE), General Superintendent (GS), Foreman and any individuals directly involved with the initial near hit. This review would be treated the same as an incident review where a loss has happened. Not all near hits would require this type of review but; near hits scoring a 4-5 on the Matrix scale would indicate serious conditions that warrant further investigation.
If the investigation or evaluation turns up a condition that could affect other projects the near hit should be discussed in the following OPS meeting. If it determined that this could have an impact in other Branches, this should be shared with the SPS and Corporate Safety Teams. Past experiences have shown that the sharing of this information has been highly successful in identifying conditions elsewhere in the company. As an example, in one part of the company, a hard hat inspection ended in the replacement of dozens of defective hard hats across the country.
Once the Near Hit Forms are complete, the information gained from the Near Hit Form must be recorded. This recording process aids in future statistical analysis of potential problem areas. Documented information such as time of day, body part
effected, root cause analysis, and contributing factors create a data base of information that can be used for future focused areas. An example might be that several near hits
Matrices Used in Safety Management
indicated lack of training or knowledge as a contributing factor. We would then need to take a close look at that part of our system in which training needs are determined. Risk Analysis
The application of the Matrix allows us to focus on areas that pose the greatest risk. Past data has shown that less than 20 percent of the reported near hits are considered significant in terms of overall risk. In a study performed for the U.S Atomic Energy Commission and published in The Management Oversight and Risk Tree (MORT) by W.G. Johnson, reference to the Pareto Principal as a management emphasis tool in the decision making process for focusing on the “critical few” or the “insignificant many”. The critical few, refers to the few conditions that will be the most costly in terms of loss or injury. The insignificant many is in reference to the bulk of instances that have little or no effect to the overall safety.
Matrices have been used to analyze deployment of preventative measures by the United Kingdom Atomic Energy Authority since 1967. Three areas of emphasis are generally brought up by these matrices:
1. focus on all issues found,
2. focus on high frequency, low severity issues 3. or, focus on low frequency, high severity issues.
Most studies have concluded that the area of emphasis involving low frequency and high severity should be the focal point of concern.
Matrices Used in Safety Management
Heinrich’s early observations of incidents showed that the frequency of unsafe acts and conditions were relative to the number of injuries. Though there were several more unsafe acts and conditions than injuries, the thought was that by lowering the number of unsafe acts and conditions, that this would create a relatively lower number of injuries. This would require acting on all incidents from the insignificant many to the critical few. Per the Pareto Principal we would be spending 80 percent of our time on the 80 percent that did not make an appreciable difference.
A degree of residual or acceptable risk must be calculated to determine levels of priority. Risk assessment requires a measuring tool that takes into account severity of an exposure to a hazard and the potential of an incident to occur. Using past incidents including near hit data, incident reports and personal experience, ratings can be given variables such as likelihood and severity to determine and calculate exposure.
Probability
The likelihood of the occurrence could be rated in the following:
0 = Will not happen 1 = Very unlikely 2 = Could happen 3 = Has happened 4 = Likely to happen
5 = Will occur (imminent danger) (example 1)
Matrices Used in Safety Management
Severity
In terms of rating the severity of the occurrence the following example could be used:
0 = no harm 1 = first aid only
2 = Dr visit no lost time
3 = Dr visit w/ lost time (temp disability/ temp partial/ temp total) 4 = Dr visit w/ lost time (perm. Disability/ perm part/ perm total) 5 = Death
(example 2)
Utilizing the parameters, 0-5, with the associated descriptors, we can calculate numbers along an index (discrete variable).
The following mathematical formula can be used to determine the score for each task:
Index Calculation R = S x L
Where L equals the Likelihood of an occurrence,
S equals the severity or potential severity of an incident, R would represent the number given on the index. (example 3)
The parameters for severity and likelihood are zero to five (0-5) with the index (discrete variable) ranging from 0 – 25, zero being the lowest risk and 25 the highest.
Matrices Used in Safety Management
Index 0 = 0x0, 0x1, 0x2, 0x3, 0x4, 0x5 0 = 1x0, 2x0, 3x0, 4x0, 5x0 1 = 1x1 2 = 1x2, 2x1 3 = 1x3, 3x1 4 = 1x4, 4x1, 2x2 5 = 1x5, 5x1 6 = 2x3, 3x2 8 = 2x4, 4x2 9 = 3x3 10 = 2x5, 5x2 12 = 3x4, 4x3 15 = 3x5, 5x3 16 = 4x4 20 = 4x5, 5x4 25 = 5x5 (example 4)
Determinations can then be made along the line from 0 to 25 using supporting data. Labels then can be applied to these determinations such as minimum, minor, moderate, high, imminent danger.
Determination Labels Minimum risk (0-2)
1x2 very unlikely x Dr visit no lost time 2x1 could happen x 1st aid only
Minor risk (3-4)
1x3 unlikely x temp disability 3x1 has happened x 1st aid only
1x4 unlikely x perm disability 4x1 likely x first aid only
2x2 could happen x no lost time Dr visit only Confidential: Any unauthorized use or distribution is prohibited.
Matrices Used in Safety Management
Moderate risk (5-8)
2x3 could happen x lost time 3x2 has happened x no lost time
2x4 could happen x Dr visit/ lost time/ temp disability 4x2 likely to happen x Dr visit no lost time
1x5 very unlikely x death 5x1 will occur x 1st aid only
High risk (9-12)
2x5 could happen x death
3x3 has happened x lost time temp disability 3x4 has happened x Dr visit perm disability 4x3 likely to happen x lost time temp disability
Imminent danger (15+)
3x5 has happened x death
5x3 will occur x lost time temp disability (example 5)
Charting these numbered pairs we can apply a color coding to give a visual representation of areas with the highest risk. Red would be representative of those areas requiring immediate action, yellow would represent areas of concern, while green would represent areas that would not require immediate action.
Matrices Used in Safety Management
Ordered Pairs (1) 5 5x0 5x1 5x2 5x3 5x4 5x5 4 4x0 4x1 4x2 4x3 4x4 4x5 3 3x0 3x1 3x2 3x3 3x4 3x5 2 2x0 2x1 2x2 2x3 2x4 2x5 1 1x0 1x1 1x2 1x3 1x4 1x5 0 0x0 0x1 0x2 0x3 0x4 0x5 0 1 2 3 4 5 (example 6)
Another example would change the parameters from 1-5, removing the descriptors “would not happen” for probability and “no harm” for severity since their presence makes no appreciable difference.
Ordered pairs (2) 5x1 5x2 5x3 5x4 5x5 4x1 4x2 4x3 4x4 4x5 3x1 3x2 3x3 3x4 3x5 2x1 2x2 2x3 2x4 2x5 1x1 1x2 1x3 1x4 1x5 (example 7)
Other Uses for the Matrix
The premise of this section is to present the operational steps for the reporting, recording and analysis of near hits however, matrices can be used in other safety management areas to assess tasks and process with recognized hazards that have the potential to cause harm. As was discussed in the beginning of this paper, the purpose of assessing risk is to determine areas of greatest liability by prioritizing tasks, equipment and procedures that require immediate action. Performing a task hazard analysis prior to an operation is an excellent way to investigate areas of exposure and place controls
Matrices Used in Safety Management
to prevent exposures. Controls can be prescribed after evaluation using a risk based matrix that takes into consideration both the severity and probability of occurrence.
Task Hazard Analysis (THA) for Radial Arm Saw Operation
Task step Hazard Severity Probability Index
1.Pick up
boards Back strain 3 2 6
2.Carry to saw Slip,Trip,falls 3 1 3
3.Stack boards Pinch fingers 1 4 4
4.Place board in saw
No known
hazard 0 0 0
5.Cut board Cut finger 4 2 8
(example 8)
In example 8, under task steps, step number one indicates that boards are picked up. The potential injury would be back strain. This has a severity rating of three for possible lost time injury (example 1) and a two in the probability column for the potential of occurrence (examples 2). This example gives us an index score of nine (example 4). Per the ordered pair, 3x2, this would be found in the Moderate Risk category (example 6). Step five also scored in the Moderate range with an eight.
Though eight is in the moderate range it is on the high end only one point from the high risk category.
The last step for consideration is the control of hazards. The hierarchy of controls are as follows:
Matrices Used in Safety Management
2. Substitution
3. Engineering Controls 4. Administrative Controls
5. Personal Protective Equipment (PPE)
The order in which the controls are used should remain the same with elimination of hazards remaining as the first choice for hazard control and PPE as the last line of defense.
No Matrix With Matrix
Matrices Used in Safety Management
A B C D E F
Respondents Ex 1 Ex.2 Ex.3
W/ Matrix Ex.1 W/ Matrix Ex.2 W/ Matrix Ex.3 1 1 4 5 5 4 5 2 3 5 4 5 4 4 3 5 5 3 5 4 5 4 2 4 5 4 4 5 5 3 5 5 5 4 5 6 5 4 3 5 4 5 7 4 3 5 5 4 5 8 3 4 4 4 4 5 9 4 4 5 5 4 5 10 2 4 5 5 4 5 11 3 5 5 5 4 4 12 5 5 4 4 4 5 13 2 4 3 5 4 5 14 3 5 5 5 4 5 15 5 4 5 5 4 5 16 4 3 3 5 4 5 17 3 4 5 5 4 5 18 4 4 4 4 4 5 Mean 3.3889 4.2222 4.3333 4.7778 4 4.8889 Stan. Dev 1.13 0.6667 0.8864 0.4278 0 0.3234 Mode 3 4 5 5 4 5 Median 3 4 4.5 5 4 5
The columns A, B, and C are ratings given 3 separate Near Hits Reports by 18 respondents. Example number one (1), a ladder inspection that located a ladder with split rails and a bent rung. Example number two (2) included sparks falling to a lower public area during a torch cutting operation. Example number three (3) involved a hole located on an elevated deck large enough for someone to fall through that was not protected.
Columns H, I and J are the exact same scenarios, but the respondents were asked to use the Near Hit matrix represented on sheet 2 of this spread sheet to determine their ratings.
With the data distribution being approximately normal then about 68% of the values are within 1 standard deviation of the mean, about 95% of the values are within two standard deviations, and 99.7% lie within 3 standard deviations. With a statistical certainty we can say that the use of the Matrix format would result in more reliable data for the field for use in determination of actions immediately after occurrence and achieve more reliable data for documentation of near hits throughout the company.
Matrices Used in Safety Management
Catastrophic
fatality/permanent disability
Critical
lost time injury
Ilness Medical onlyno lost time first aid onlyMarginal
Negligible incident report only Frequent common or repeated occurrence 25 (5) Operation not permissible 20 (5) Operation not permissible 15 (5) Operation not permissible 10 Operation not permissible 5 High Priority Remedial Action Probable known to occur "it has happened" 20 (5) Operation not permissible 16 (5) Operation not permissible 12 Operation not permissible 8 High Priority Remedial Action 4 Acceptable risk remedial action is discretionary Occational
could occur, "I've heard of it happening" 15 (5) Operation not permissible 12 Operation not permissible 9 Operation not permissible 6 High Priority Remedial Action 3 Acceptable risk remedial action is discretionary Remote Not likely to occur 10 Operation not permissible 8 High Priority Remedial Action 6 High Priority Remedial Action 4 Acceptable risk remedial action is discretionary 2 Acceptable risk remedial action is discretionary Improbable practilly impossible may assume it will not happen 5 High Priority Remedial Action 4 Acceptable risk remedial action is discretionary 3 Acceptable risk remedial action is discretionary 2 Acceptable risk remedial action is discretionary 1 Acceptable risk remedial action is discretionary
