Enterprise applications are now emerging from nearly a decade-long drought of focus on user interaction and usability engineering. The causes of this period of neglect are numerous, and include: computation and connectivity values, information availability, throughput and performance improvements, the diminished value of high-level UI variations, and the alignment of usability engineering as a marketing component rather than a proponent of efficient business operations. The current Global User Experience is primed for a resurgence of focus on usability, particularly within the enterprise applications arena. The major drivers originally leading to neglect have now pivoted into drivers promoting the discipline. Computation and connectivity has grown beyond the ability of users to identify the scope and meaning of information available to them. Task performance improvements from digital computation have plateaued; further improvements require new human-related factors. Now all levels of the user interface architecture can be modified quickly and the wide variations in user interface interactions offer real business value though user interface design. The value of usability engineering as a partner to efficient business operations is becoming more evident as well. A pertinent area of focus is Critical Interactions. These are the steps in business processes where the important decisions are made, and where user actions critically affect task performance. Using relevant corollaries from safety-critical system design, the prime areas and methods for incorporating usability design, task analysis and user performance factors into enterprise application development are explained, with a focus on identifying critical interactions and improving the success rate of critical task completion.