Nowadays, many management methods are used in the implementation of investment processes. Their common attribute is optimising the total cost of implementing an investment project by reducing all types of costs at each stage of the process. This is particularly important if the investment process is very complex since it is implemented according to the idea of modular construction. The aim of this study is to identify those modern management methods that improve the investment process by leading to the optimisation of the costs involved. These methods refer to the management process of the investment project (Agile Scrum Method, Kanban Method, Lean Construction Method) or directly to the management of the costs generated by the project (Activity-Based Costing). Together these methods will contribute to optimising the total cost of the project. Moreover, their applicability means they can be directly implemented or modified in any investment project that utilises modular construction. The features of the mentioned methods were identified and adapted to the specificity and requirements of the investment process in modular construction using the desk research method. As a result, it has been noticed that the use of management methods such as Agile Scrum, Lean Construction and ABC are crucial in the implementation of modular construction projects due to their ability to streamline processes, increase cost and time efficiency, and enable flexibility in the event of changing requirements.