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8.2 Accident Preventation Process

1. Pareto Analysis, Fish Diagram, Gantt Chart, Job Worksite Analysis Guideare several methods that can be used in the first step for accident

prevention process. Chi-Square Analysis

Another tool that is very effective in identifying wether one department

is significantly more hazardous is chi-square analysis. Chi-square

analysis is based on chi-square goodness of fit test between sample and

population distribution in the form of categorical data in contingency

table.

Number of injuries in processing is found from :

()

Ei = Expected Value = Hix OT/HT =(exposure x total injuries/ total exposure)

Oi = Observed Value

OT = Total of observed value

Hi = Hours Worked

HT = Total of hours worked

m = Number of areas compared

Result greater than a, m-1, the critical at an error level of and m-1 degrees of freedom, so it will be significant difference

between the expected and observed values in injuries.

2. Collect and Analyze Data- Job Safety AnalysisCollect and analyze datajob safety analysis is the second and third steps

of the accident prevention process. We can called it JSA or Job Hazard

Analysis or Method Safety Analysis. Based on JSA safety engineer should

focus on four major factors.

a. Worker ; supervisor, operator, employeeb. Method ; the work procedure during the processc. Machine ; the equipment that being usedd. Material ; raw material, components, or something that being used

in the process

So, an improvements could involve for the better training for the operator,

a new method, safer equipment and tools, and also better materials and

components. JSA provide several useful features that cross over into methods

engineering. They are simple, quick and objectives and it means of mapping

all the relevant details.

They also can compare exiting and proposed methods with potential

effects not just on safety but also on production, which is very useful

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application in terms of selling increased safety to management. JSA approach

can be made more quantitative by adding probabilities, which leads into the

very quantitative fault tree anaylsis.

3. Select a RemedyRisk Analysis and Decision MakingRisk Analysis is more suitable for safety because it calculates the potential

risk for an accident or injury and the reduction of risk due to modifications.

The analysis is based on the premise that the risk for injury or loss cannot

be completely eliminated. According to the method the potential loss

increase with.

1. Increased likelihood or probability that the hazardous event will occur.2. Increased exposure to the hazardous conditions.3. Increased possible consequences of the hazardous event.

Numerical values are assigned to each of the above three factors. These

numerical values are rather arbithary and consequently the final risk score

is also rather arbithary. However, doesnt negate the method it still serves

as method to provide good relative comparison between different safety

features of controls.

4. Monitoring and Accident StatisticsThe sixth and final step in accident prevention process is

Monitoring and accident statistics. The objectives is to evaluate the

effectiveness of the new method. This is provide feedback on the

process and closes the loop by restarting the recycle in case thesituation is not improving. Numerical data provide a solid benchmark

for monitoring any change. That could be ;

1. Insurance Cost2. Medical Cost3. Simply numbers of injuries/ accidents

Any of these number should be normalized to the worker exposure

hours so that, the number can be compared across locations and

industries. OSHA recommends expressing injury statistics as incidence

rate( IR) per 100 full-time employees per year.

IR = 200,000 X I/H

I = Number of Injuries in given time period

H = Employee hours worked in the same periods

Record keeping purposes, the injuries should be OSHA-recordable, or

more than simple first aid injuries. Similarly, the severity rate (SR)

monitors the number of lots time ( LT ).

SR = 200.000 X LT/ H

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To simply recording and monitoring the incidence rates as they change

from month to month, the safety engineer should apply statistical control

charting principles and look for long term trends.

The control chart is based on normal distribution of the data

established a lower control limit ( LCL ) and a upper control (LCL) as defined

LCL =nsUCL =+ ns= sample means = sample of standard deviation

n = level of control limits

For tracking accidents or injuries, the control chart is rotated sideways

and the monthly data are plotted on the chart. The lower control limit is less of

concern than upper control limit, so this should be red flag or signal to the

safety engineer that there is a problemand serious effory should have noticed .

Trend analysis could be easily performed using a moving linear regression

ever varying multiple month periods.