Job safety analysis (JSA)

What is job safety analysis?

Risk assessment identifies the risks of a job as a whole; job safety analysis goes a step further and examines a specific task, step by step, as it is performed in practice. Its fundamental question is twofold: what can go wrong at each step and what needs to be done to prevent it. The result is a short, tabular document that becomes the basis for job instructions, on-the-job training, and task observation.

The method became popular in the United States, where OSHA describes it in its publication on job hazard analysis, and has spread to industry and construction worldwide under different names: AST, JSA, JHA, and job safety analysis. In Spain, the INSST (National Institute for Safety and Health at Work) does not regulate it as such, but incorporates the same logic in its documents on work instructions and safe work procedures, particularly in NTP 560, and Law 31/1995 requires that preventive measures be integrated into task instructions and that workers receive job-specific training.

The AST is especially useful in tasks with previous accidents, in new or modified tasks, in those that depend heavily on the way they are executed, and in those carried out by contractors or new personnel.

How it is done

1. Select the task: by potential severity, frequency of accidents or incidents, novelty, complexity, or dependence on the human factor.
2. Form the team: the person who usually performs the task, their direct supervisor and, where appropriate, the prevention or maintenance service; analysis without those who perform the work produces procedures that nobody follows.
3. Break down the task into steps: between five and fifteen, ordered, describing what is done and not how it should be done; observe the actual execution, not the one described in the manual.
4. Identify the hazards of each step: contact with energy, falls, entrapments, exposure to agents, exertion, environmental factors, interaction with other tasks.
5. Define the control measures step by step, following the hierarchy: eliminate the step or hazard, substitute, protect collectively, organize, and only at the end individual protection and conduct.
6. Draft the safe work instruction with the result, validate it with the team and approve it; train the affected people and observe the application.
7. Review the analysis when the equipment, process or conditions change, after an accident or incident, and with the frequency set by the company.

A common format is a three-column table: step, hazards, measures. The resulting document should fit on one or two pages and be written in the language of the intended user.

Relationship with risk assessment and other tools

• Risk assessment. Mandatory and comprehensive per position; the AST develops it for specific tasks and may detect risks that the assessment did not cover, which requires updating it.
• Work instruction. An operational document that describes how to perform the task safely; it is the product of the JSA.
• Work permit. Specific authorization for a particularly high-risk intervention; it is usually based on a prior Job Safety Analysis (JSA) of the task.
• Planned observation of the work. Check if the task is performed as instructed and provide feedback for the analysis.
• Root cause analysis . When an event occurs, check if the AST existed, if it was adequate, and if it was applied.

Organizational application

• Inventory of critical tasks. Each area identifies the tasks that require AST and prioritizes them; the list is reviewed annually.
• Line responsibility. The AST is led by the area manager with the people who perform the task; the prevention service advises and validates.
• Integration with training. The resulting instruction is the on-the-job training material and the reference for welcoming new hires and contractors.
• Documentation. The ASTs are kept as part of the preventive documentation and are linked to the job assessment and work permits.
• Digitization. Management platforms allow you to keep ASTs updated, link them to equipment and workstations, distribute them on mobile devices, and record their review.

Limits and common mistakes

1. Drafting the AST in the office without observing the actual task or involving those who perform it.
2. Breaking the task down into too many or too few steps reduces its usefulness.
3. Identify generic hazards (“bumps”, “falls”) without linking them to the specific step or its cause.
4. Addressing all hazards with personal protective equipment and “be careful” warnings, without considering technical or organizational measures.
5. Confusing the AST with risk assessment and considering the legal obligation fulfilled with a collection of task-based analyses.
6. Do not review the ASTs when equipment or processes change, so they describe tasks that are no longer done that way.

The AST does not replace the specific assessments required by specific standards (noise, chemical agents, handling of loads, display screens) nor the mandatory work procedures for certain risks, such as electrical ones.

Regulatory framework and technical references

• Law 31/1995, articles 16, 18 and 19. Evaluation and planning, information on the risks of each position and training specifically focused on the job or function.
• Royal Decree 39/1997, articles 1 and 4. Integration of prevention into the set of activities and decisions, and content of the evaluation by job position.
• NTP 560: Preventive management system: procedure for preparing work instructions (INSST) . Criteria for preparing work instructions that integrate prevention.
• OSHA 3071, Job Hazard Analysis . US reference guide on the method; not currently in force in Spain.

In Colombia and other Latin American countries, Job Safety Analysis (JSA) is widely used and, in some cases, required by sector-specific regulations, such as those governing work at heights. The ILO-OSH 2001 guidelines do not mention it by name, but they do include hazard identification and risk control at the task level as part of the management system.