America's fire departments are busier than ever, responding to both emergency and non-emergency calls that have dramatically increased over the last several decades (National Fire Protection Association [NFPA], 2021b). This dissertation in practice analyzed the on-duty training model of a mid-sized fire department in the northwestern United States, where increased calls and other factors have limited on-duty training required for firefighters to operate on emergency incidents safely and effectively (Thiel et al., 2003). The problem of practice is that there was insufficient time for formal on-duty training at the fire department studied. This dissertation in practice explored peer-to-peer learning, group learning, virtual learning, crew rotations, and external training opportunities as potential improvements to the problem of practice. The purpose was to develop and present a best practices playbook that improves on-duty training at the department. Structured peer-to-peer learning was selected as the improvement medium, and a qualitative study was undertaken to learn about the training experiences, ideas, and observations of firefighters who work here. Specifically, twelve firefighters of different rank, tenure, and background were asked to address learning infrastructure and culture, on-duty training and peer-to-peer learning experiences, and any barriers to effective on-duty training. The study concluded that peer learning is culturally prevalent in this fire department, and structured peer learned, if performed correctly, could create a new training medium not currently realized. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]