This document discusses applying systems design methods to improve primary care physician (PCP) workflow. It develops a Domain Mapping Matrix (DMM) to clarify the relationships between major tasks in PCP workflow and elements of the PCP organization. The DMM identified six major clusters of relationships between 12 PCP workflow tasks and 25 organizational elements. The DMM shows where coordination across domains is most intense and can help standardize PCP workflow protocols with the Electronic Health Record (EHR) and Nursing Notes playing pivotal roles.