There are many terms that can be used as synonyms for the phrase "random investigations." Some common alternatives include unplanned inspections, unexpected audits, unscheduled reviews, impromptu assessments, and ad-hoc inquiries. All of these phrases suggest a process of examining something without prior notice or intention, and can be used in various contexts. For example, unexpected audits may be conducted at businesses to ensure compliance with regulations, while impromptu assessments may be used to gather feedback from employees about workplace conditions. When seeking to convey the idea of conducting an investigation without specific planning, there are many synonyms to choose from.