Commissioning is a process for ensuring that a system is designed and operated as intended; commissioning helps achieve larger goals of sustainable design and operation, Life Cycle Cost (LCC) effectiveness, efficient use of investments, minimizing overall maintenance and utility costs, component life reliability and performance expectations. AiCARR, ASHRAE and CIBSE have agreed to draw from definitions and terminology that appear in their publications or in their other resources for the purpose of harmonization by developing a first collective work on the topic. This workshop presents the state of terminology in each country and a proposal for a common overview.