*3.1. Concept of BATM*

As previously stated, the existing project management maturity models and BIM maturity models have obvious deficiencies in evaluating the management level of engineering projects with BIM applications. Against the background in which the idea of digital twins has become popular and 37 desired outcomes of the PMBOK 7th edition have become an acceptable global standard, in order to enable an organization to accurately understand the capabilities of its project management and BIM applications and then take effective measures for improvement, the PBM and PBA maturities can be evaluated simultaneously based on each desired outcome.

It is in this context that the BATM model is proposed. The BATM is expressed by a two-dimensional value such as (x, y), in which x reflects the PBM maturity level, and y reflects the PBA maturity level. The BATM model consists of the following items: maturity level definition, assessment indexes, questionnaire, maturity calculation and problem identification methods, improvement advice, etc.

The purpose of putting forward the concept of BATM is to use the PBM and PBA maturities to reflect the level of enterprises' project management and project BIM applications; and, through the BATM model, determine enterprises' strengths and weakness in the PBM

and PBA aspects, identify the improvement directions, and promote the advancement of enterprises' PBM and PBA maturities.

It is noteworthy that the two-dimensional maturity in this study differs significantly from the multi-dimensional maturity in other studies. The two dimensions investigated in this study were the PBM of the real world and the PBA of the virtual world. For example, considering "Effective management of procurements" which is one desired outcome of the project work performance domain in PMBOK 7th edition, the BATM value of (3, 1) means that the PBM maturity level of procurement management in the real world is 3 and the PBA maturity level in the virtual world is 1; it also means that there are obvious deficiencies in its online capabilities for supporting offline project management. However, the multiple dimensions in other studies refer to several aspects of pure project management. For example, Hu presented a three-dimensional PMMM constituted by best practice maturity, process maturity, and organization system maturity [53].
