Companies in the oil and gas industry strive to increase their performance in Engineering, Procurement, Construction, and Installation projects. New responsibilities of the Company within this research, encounter unforeseen surprises in an early project phase called As‐Is Engineering. No prioritization for documenting and communicating working processes and key‐personnel dependency are the symptoms related to the Company's challenges. To cope with the Company's challenges, this research investigates the development of a process architecting tool to facilitate future working processes. Given a known method of A3 Architectural Overviews from Systems Engineering for communicating architectural knowledge, we applied it together with process mapping to develop a process architecting tool for the Company. Through literature review and workshop testing with loops of feedbacks in the Company, a process architecting tool ‐ Operational A3 is proposed. Results from surveys and interviews show the Operational A3 benefits the Company in terms of increased project performance.