Computerized software tools are assuming major significance in conducting HAZOPs. This is because they have the potential to offer better online presentations and performance to HAZOP teams, as well as better documentation and downstream tracking. The chances of something being "missed" are greatly reduced. We know, only too well, that HAZOP sessions can be like the industrial equivalent of a trip to the dentist. Sessions can (and usually do) become arduous and painstaking. To make the process easier for all those involved, we need all the help computerized software can provide. In this paper I have outlined the challenges addressed in the production of Windows software for performing HAZOP and other forms of PHA. The object is to produce more "intelligent", more user-friendly software for performing HAZOP where technical interaction between team members is of key significance. HAZOP techniques, having already proven themselves, are extending into the field of computer control and human error. This makes further demands on HAZOP software and emphasizes its importance.