Acting assignments are one of the most powerful and least examined advancement tools. In Minnesota state service, the formal version is called a work out of class assignment. State administrative procedure describes it as a temporary assignment in which a permanent or probationary classified employee performs substantially all the duties of a temporarily unoccupied position in a different classification. Pay may be adjusted as required or permitted by the applicable labor agreement or compensation plan, time limits apply, longer assignments need additional approval, and the appointing authority may end an assignment at any time. The details depend on the labor agreement, so HR is the partner for how any specific assignment works.
Acting assignments matter because they create exactly the experience that later selection processes reward. Someone who acted as a supervisor for six months has a track record that others do not. If these assignments go to whoever is nearest, whoever the departing leader recommended or whoever asked first, the pattern compounds over time. A fair approach sets out, in advance, how interim opportunities will be offered, uses job-related criteria, and rotates when there are several qualified people. Explaining the choice to the team is part of fairness too.
It helps to be clear about the boundary between what a supervisor can change and what needs a partner. A supervisor can: state plainly what advancement requires, rotate visible and acting opportunities, hold career conversations with everyone, keep position descriptions accurate, and sponsor people. A supervisor needs a partner for: classification questions and reallocation requests, pay equity reviews, anything governed by a labor agreement, and formal selection. Those go to HR classification staff, labor relations and leadership.
When you bring a concern to HR, bring the pattern you noticed and describe the people affected in general terms, not a case built around one person. For example: over two years, most acting lead roles in our unit went to staff in one location, and staff who work mainly with Tribal partners have not had one. Patterns point to changes in practice. A single case can turn a systems question into a dispute about one person, and may raise privacy concerns under the Minnesota Government Data Practices Act.