In high-risk industries, Permit-to-Work (PTW) systems are widely used to authorize and control hazardous activities. However, many international companies also implement behavioral safety tools to complement formal procedures. One such tool is the Job Safety Analysis (JSA), which engages frontline workers in step-by-step risk assessments and promotes real-time hazard awareness.

Both PTW and JSA are designed to prevent incidents by identifying hazards and ensuring that appropriate controls are in place. Given their overlapping functions, a natural question arises: is it really necessary to use both PTW and JSA for the same task?

To better understand this, let's consider each component individually.

A Permit-to-Work is a formal authorization for a crew to perform high-risk tasks. It is issued by an authorized person to the performing authority, and together they typically determine the required safety measures. The PTW ensures a baseline level of safety during high-risk activities and restricts access to authorized personnel only. It is used for specific categories of hazardous work, such as Lockout\Tagout, confined space entry, or hot work.

A Job Safety Analysis (JSA) is a worker-driven risk assessment tool, similar to TSTI (Total Safety Task Instruction) or Task Hazard Analysis (THA) commonly used in the U.S.  It involves breaking down the task into steps, identifying key hazards at each step, and determining appropriate safety controls. The main goal is to raise situational awareness among workers.

In my experience, workers often know the safety rules but fail to apply them because they don’t connect the rule to a specific risk in their current task. JSA helps bridge this gap between theory and practice. Through collaborative development, workers share knowledge, feel more engaged, and take ownership of the safety measures. It’s well known that people are more likely to follow rules they've helped create.

There has been growing discussion in the U.S. about allowing teenagers to perform hazardous tasks, and about the tools that could help them prepare. Based on conversations with employees during workshop visits, I’ve found that participating in group TSTIs helps younger workers integrate more quickly and learn safety expectations in a practical way.

The article  Mikkelsen, K. L., Spangenberg, S., & Kines, P. (2019). The application and benefits of job safety analysis. Safety Science, 113, 425–432, identifies six key benefits of Job Safety Analysis (JSA): it formalizes work processes, promotes worker participation, improves situational awareness, enhances organizational learning, strengthens accountability, and helps prevent losses in dynamic environments. These benefits support both safety and operational efficiency. 

Real-World Comparison

To illustrate the practical application, let us compare PTW and JSA using a real-world scenario.

A team of three workers is assigned to repair a storage tank. The department manager issues a PTW to the performing authority. The permit states that the tank must be emptied before work begins, and a Lockout/Tagout (LOTO) procedure must be applied. A lab team must also test the air inside the confined space before entry. The PTW also specifies who will serve as the attendant and who will enter the tank.

Draining the tank is handled by technicians, air monitoring by the lab, and LOTO is performed by both the maintenance crew and production staff. The performing authority is responsible for ensuring all the requirements in the PTW are fulfilled.

Meanwhile, the crew and the performing authority work together to complete the JSA. They break the job into steps. The first step is opening the tank. Technically, the tank should be empty — but there’s always a risk it isn’t. In one case I’ve seen, a faulty sensor showed the tank was empty, but when the worker opened it, hot liquid poured out.

A PTW wouldn’t normally account for that level of detail. But the JSA captures it. The crew lists the hazard, explains the cause (sensor failure), and adds a safety control: loosening the bolts on the hatch gradually, so if any liquid remains, it will seep out slowly and give them time to react.

Another risk: Someone could accidentally introduce liquid into the tank while work is in progress. The PTW may mention isolation, but the JSA reinforces the need for each worker to apply their own lock on the valve or lockbox, even if someone else has already done so.

As this example shows, the PTW and JSA cover similar risks, but they are directed at different people and serve different goals:

• PTW ensures the job is organized safely from a management and procedural standpoint.
• JSA promotes a safety culture, raises awareness, and helps workers learn from each other and apply best practices in real time.

When implementing JSA, it’s critical for workers to understand how it differs from a Permit-to-Work and how the two should be used together.

A colleague recently shared a story that highlights this:

A contractor team was assigned a job under a PTW issued by a client representative. The permit was a one-page checklist, with tick boxes for each required safety measure. One box was checked: "wear chemical suits." The performing authority, together with the crew, completed a JSA and determined that chemical suits were only necessary during the highest-risk phase. They wore the suits during that part, then removed them to complete the rest of the task.

During this time, a safety officer visited the site and found the team not in compliance with the PTW. The work was stopped.

This situation illustrates a clash between formal and behavioral safety approaches.

The team showed a high level of safety culture by conducting a thoughtful JSA. However, they misunderstood the status of the PTW. On a client site, the PTW is non-negotiable unless changes are officially approved by the issuing authority. Even if the crew’s risk analysis made sense, the protocol was clear — chemical suits were required throughout the task.

What could the performing authority have done differently?
Ideally, they should have been more involved in the PTW issuance process and requested clarification: which phases of the work required chemical suits?
When the permit issuer and the performing team are from the same company, such discrepancies are easier to avoid. In fact, a good practice is to prepare the PTW and JSA simultaneously and attach the JSA as a supporting document.

But when contractors work on a client's site, a different approach is needed:

• Train teams to understand that JSA complements but does not override PTW.
• Establish a clear procedure for requesting PTW modifications when JSA reveals excessive or unclear controls.
• Define and communicate who has the authority to amend the PTW within the safety management system.

Different purposes

In summary, while both Permit-to-Work (PTW) and Job Safety Analysis focus on ensuring safety during high-risk tasks, they serve different purposes. PTW is a formal, management-driven system designed to ensure that safety measures are in place before work begins. It focuses on procedural compliance and restricts access to authorized personnel. JSA, on the other hand, is a worker-driven approach that emphasizes risk awareness at every step of the task, helping to bridge the gap between safety theory and practical application. By fostering collaboration and engagement among workers, JSA enhances safety culture and allows for real-time hazard identification. However, it’s crucial to remember that JSA complements PTW, not replaces it. Any adjustments or clarifications to the PTW must go through the official approval process. Integrating both systems ensures a comprehensive safety approach that balances formal procedures with active participation and awareness on the job.