Job safety analysis

A job safety analysis (JSA) is a procedure which helps integrate accepted safety and health principles and practices into a particular task or job operation. In a JSA, each basic step of the job is to identify potential hazards and to recommend the safest way to do the job. Other terms used to describe this procedure are job hazard analysis (JHA) and job hazard breakdown.
The terms "job" and "task" are commonly used interchangeably to mean a specific work assignment, such as "operating a grinder," "using a pressurized water extinguisher" or "changing a flat tire." JSAs are not suitable for jobs defined too broadly, for example, "overhauling an engine"; or too narrowly, for example, "positioning car jack."
Hazard controls.
Controls are the barriers between people and/or assets and the hazards.
A hard control provides a physical barrier between the person and the hazard. Hard controls include machine guards, restraint equipment, fencing/barricading.
A soft control does not provide a physical barrier between the person and the hazard. Soft controls include signage, procedures, permits, verbal instructions etc.
Control effectiveness criteria.
The effectiveness of a control is measured by its ability to reduce the likelihood of a hazard causing injury or damage. A control is either effective or not.
To gauge this effectiveness several control criteria are used, which:
There is no commonly used mathematical way in which multiple controls for a single hazard can be combined to give a score that meets an organisations acceptable risk level. In instances where the residual risk is greater than the organisations acceptable risk level, consultation with the organisations relevant risk authority should occur.
Hierarchy of control.
Hierarchy of control is a system used in industry to minimize or eliminate exposure to hazards.
It is a widely accepted system promoted by numerous safety organizations. This concept is taught to managers in industry, to be promoted as 
a standard practice in the workplace. Various illustrations are used to depict this system, most commonly a triangle.
The hierarchy of hazard controls are, in descending order of effectiveness: Elimination, Substitution, Engineering, Administration and Personal Protective Equipment. In some systems, Isolation is included in the list of controls. The list then is Elimination, Substitution, Isolation, Engineering, Administration and Personal Protective Equipment.
Scope of application.
A JSA is a documented risk assessment developed when company policy directs employees to do so. Workplace hazard identification and an assessment of those hazards may be required before every job.
JSAs are usually developed when directed to do so by a supervisor, when indicated by the use of a first tier risk assessment and when a hazard associated with a task has a likelihood rating of 'possible' or greater.
Generally, high consequence, high likelihood task hazards are addressed by way of a JSA.
These may include, but are not limited to, those with:
A history of, or potential for, injury, harm or damage such as those involving:
It is important that employees understand that it is not the JSA form that will keep them safe on the job, but rather the process it represents. It is of little value to identify hazards and devise controls if the controls are not put in place. Workers should never be tempted to "sign on" the bottom of a JSA without first reading and understanding it.
JSAs are quasi-legal documents, and are often used in incident investigations, contractual disputes, and court cases.
Structure of a JSA.
The JSA or JHA is usually created by the work group who will perform the task. The more minds and experience applied to analysing the hazards in a job, the more successful the work group is likely to be in controlling them. Sometimes it is expedient to review a JSA that was prepared when the same task was performed on a previous occasion, but care should be taken to ensure that all of the hazards for the job are controlled for the new occasion. The JSA is usually recorded in a standardised tabular format with three to as many as five or six columns. The headings of the three basic columns are: Job step, Hazard and Controls. A Hazard is any factor that can cause damage to personnel, property or the environment (some companies include loss of production or downtime in the definition as well). A Control is any process for controlling a hazard. The job is broken down into its component steps. Then, for each step, hazards are identified. Finally, for each hazard identified, controls are listed. In the example below, the hazards are analyzed for the task of erecting scaffolding and welding lifting lugs:
Assessing risk levels.
Some organisations add columns for risk levels. The risk rating of the hazard prior to applying the control is known as the 'inherent risk rating'. The risk rating of the hazard with the control in place is known as the 'residual' risk rating.
Risk, within the occupational health and safety sphere, is defined as the 'effect of uncertainties on objectives'. In the context of rating a risk, it is the correlation of 'likelihood' and 'consequence', where likelihood is a quantitative evaluation of frequency of occurrences over time, and consequence is a qualitative evaluation of both the "Mechanism of Injury" and the reasonable and realistic estimate of "Severity of Injury".
Example:
One of the known risk rating anomalies is that likelihood and the severity of injury can be scaled, but mechanism of injury cannot be scaled. This is the reason why the mechanism of injury is bundled with severity, to allow a rating to be given. The MoI is an important factor as it suggests the obvious controls.
Identifying responsibilities.
Another column that is often added to a JSA form or worksheet is the "Responsible" column. The Responsible column is for the name of the individual who will put the particular control in place. Defining who is responsible for actually putting the controls in place that have been identified on the JSA worksheet ensures that an individual is accountable for doing so.
Application of the JSA.
After the JSA worksheet is completed, the work group that is about to perform the task would have a toolbox talk, to discuss the hazards and controls, delegate responsibilities, ensure that all equipment and personal protective equipment described in the JSA are available, that contingencies such as fire fighting are understood, communication channels and hand signals are agreed etc. Then, if everybody in the work group agrees that it is safe to proceed with the task, work can commence.
If at any time during the task circumstances change, then work should be stopped (sometimes called a "time-out for safety"), and the hazards and controls described in the JSA should be reassessed and additional controls used or alternative methods devised. Again, work should only continue when every member of the work group agrees it is safe to do so.
When the task is complete it is often of benefit to have a close-out or "tailgate" meeting, to discuss any lessons learned so that they may be incorporated into the JSA the next time the task is undertaken.