The rapid transformation of green technologies, along with increasing environmental and regulatory pressures in the maritime transport industry, has made it inevitable to reconsider investment approaches and project management practices within shipping companies. The Islamic Republic of Iran Shipping Lines, as one of the key actors in the national maritime transport sector, is facing multiple challenges, including rising energy costs, the need to reduce pollutant emissions, limited financial resources, and stringent environmental regulations. This study aimed to design a comprehensive green investment model tailored to the operational characteristics and constraints of this company.A mixed-methods approach was employed. In the qualitative phase, semi-structured interviews were conducted with industry experts and senior managers of the shipping company, and the data were analyzed using open, axial, and selective coding techniques. In the quantitative phase, a researcher-developed questionnaire was distributed among relevant managers and experts, and the collected data were analyzed using Structural Equation Modeling based on Partial Least Squares (PLS-SEM). Content validity was confirmed through expert judgment, while convergent and discriminant validity were established using AVE and HTMT indices. Reliability was also verified through Cronbach’s alpha and composite reliability, both of which indicated acceptable levels.
The results revealed that causal conditions, including employee behavior and green acceptance, demand for green investment, project budget and return, innovation, and green culture, have a significant impact on the acceptance and implementation of green investment. The core phenomenon of green investment, through activating strategies such as green project management and automation, digitalization of sales and services, green data analytics and performance monitoring systems, leads to improved investment returns, reduced energy consumption, enhanced process innovation, and increased compliance with environmental regulations.
Overall, the findings provide an effective managerial and operational framework for strategic decision-making in green investment within the shipping company and clarify the pathway toward sustainable development and reduction of environmental impacts in Iran’s maritime transport industry.