Elsewhere on the HSE website there are hints about a technique that will assist with hazard identification. In the Safety Report Assessment Guides for major accident hazard sites, the HSE lists job safety analysis (JSA) as an acceptable method. A similar term crops up in two research reports for the executive. One describes a toolkit of techniques to support behaviour change and worker engagement in small- and medium-sized construction companies, and refers to job hazard analysis (JHA) as one of the "safety programmes that were found to be most effective in reducing unsafe conditions". An earlier report on behaviour change and worker engagement in construction mentions the use of JHA as a "bottom-up worker engagement method". But while the HSE appears to accept JSA or JHA as suitable methods for identifying hazards, it offers no practical guidance on them.
The terms are used more widely in Canada and the US. The Canadian Centre for Occupational Health and Safety (CCOHS) website defines JSA as "a procedure which helps integrate accepted safety and health principles and practices into a particular task or job operation" (www.ccohs.ca/oshanswers/hsprograms/job-haz.html). It suggests four stages:
1. Select the job
2. Break the job down into a sequence of steps
3. Identify hazards
4. Determine preventive measures to overcome these hazards.
Steps 1 and 2 involve task analysis (TA), a set of techniques that became popular in the field of human factors in the 1980s. The standard text on the subject, A Guide to Task Analysis (Kirwan and Ainsworth, 1992), describes it as "any process that identifies and examines the tasks that must be performed by users when they interact with systems". The benefits include increased productivity, reduced downtime, better designed jobs and safety improvements. Kirwan and Ainsworth describe 25 TA techniques covering data collection, task description, decomposition, simulation, behaviour assessment and evaluation of the task requirements. There are, therefore, many ways that TA can be applied to JSA.
Step 1 -- choosing the job -- is critical. A poorly defined job can result in important hazards remaining unidentified, but achieving the right granularity for the job is difficult. The CCOHS explanation that "overhauling an engine" is too broad but that "positioning a car jack" is too narrow, won't help if you are risk assessing "driving for work". One TA technique that will help is hierarchical task analysis (HTA). An individual's job can be divided into tasks, then into sub-tasks, until you reach a level of description that makes identification of the hazard straightforward. Hence "driving for work" can be divided into types of vehicle, then journey types, then times of the day. Jobs at the lowest level might include "driving home from an exhibition more than 100 km later than 9pm" and "driving less than 50 km at 10am" so hazardous sub-tasks can be identified.
JSA supports the hierarchy of controls by considering where elimination or substitution is possible at a finer level of detail. For a given job role, it might not be possible to stop driving for work but perhaps distances of more than 100 km could be eliminated or driving after 9pm substituted.
Many safety and health professionals instinctively consider the elements of each job task when deciding on suitable controls. What JSA offers is a set of tools to do this, and a systematic way of applying those tools and documenting the results.
Though CCOHS favours the term JSA, the US Occupational Safety and Health Administration (OSHA) uses JHA, defining it as "a technique that focuses on job tasks as a way to identify hazards before they occur" (www.osha.gov/Publications/osha3071.pdf). The emphasis here is on identifying the hazards, rather than the CCOHS approach of integrating safety and health principles into the job. As such, JHA covers steps 1 to 3 of JSA, with the hazard prevention and management taking place after JHA is completed. At the end of its definition OSHA adds: "Ideally, after you identify uncontrolled hazards, you will take steps to eliminate or reduce them to an acceptable risk level." It is not clear what the benefit of JHA would be if the risk level is not managed.