Many organisations keep pre-completed risk assessments for particular task (such as welding). These generic documents only assess the risks that relate specifically to that task. On the other hand a site risk assessment assesses the risks of all tasks performed on the site, as well as assessing how these activities might interact and considering other site-specific factors (such as weather).
While risk assessments for specific tasks or activities can be useful, without an overall site assessment some hazards may be overlooked. For example, in a situation where two tasks are to be performed on a worksite at the same time, each worker may perform their own risk assessment, considering the risks of their own task, but may fail to take into account the hazards arising from the other activity. Likewise risk assessments may focus on the hazards of a particular task without considering how the task will be performed on site. It’s only by stepping back and considering the whole site that you can get the full picture – the site risk profile.