Purpose The purpose of this paper is to analyze the effect of a systematic commissioning process on project management performance of construction projects, expressed as cost, time, quality and customer satisfaction. The building commissioner in focus uses the term systematic completion (SC), defining it as a structured process, throughout the whole project assuring the fulfillment of functional requirements in the building. Design/methodology/approach A qualitative single case study was used to analyze the effect of a SC process by one Norwegian building commissioner in the public sector, exemplified with four projects. The analysis was conducted by studying project documents and conducting interviews. Findings SC has a positive effect on the performance of a construction project, enabling completion on cost, schedule and with fewer defects at handover. Involving facility management assures mutual learning, trained operations personnel and potentially lower costs of operations because of fewer corrections and optimized systems. Higher efforts and resource use in the early phases of the project and in testing are largely offset by the generated benefits. Research limitations/implications This case study is limited to the building commissioner's perspective in four projects. The design team's, the contractor's and the client's perspectives are not represented in the study. Only one of the projects is completed, which limits the ability to draw quantitative conclusions. Originality/value Existing studies focus on the technical aspect of SC. The present study provides valuable insights into the effect of SC on project management performance, especially on its implications for the takeover of the building by operations.