*4.3. Problems and Measures*

The BATMs of the eight performance domains are shown in Figure 1. The PBM and PBA lines represent the PBM and PBA maturities achieved in 2021, respectively. Based on the figure, we discovered the following problems: (1) the PBM maturities of two performance domains (i.e. stakeholder and measurement) are obviously lower than 2.5, and the rest are close to or more than 2.5; (2) the PBA maturities of the stakeholder and uncertainty domains are obviously lower than 1.5, and the rest are close to or more than 1.5; (3) the maturity gaps between PBM and PBA are large, in which the uncertainty and team domains are particularly prominent (their BATM values are (2.45, 1.35) and (2.71, 1.47), and the ratios of their gaps to the PBA maturities are 81.4% and 84.6%, respectively).

**Figure 1.** Assessment result of BATM model.

The obvious gaps between the PBM and PBA maturities shows that PBA not only does not guide and support PBM, but also lags far behind BPM, and there is a significant room for PBA to develop in the project, performance domain, and desired outcome layers. The organization should strengthen its support for PBA, ensure the PBA maturity catches up with the PBM maturity, and form a good interaction situation.

Through this assessment, the problems faced by the company were determined and the improvement directions were identified. In terms of the PBA maturity, the improvement priorities were the stakeholder and uncertainty domains. Regarding the PBM maturity, the improvement priorities were the stakeholder and measurement domains. In order to narrow the gap between PBA and PBM, the improvement priorities were the uncertainty and team domains.

The results of the BATM assessment aroused significant attention of the company leaders, and the company took a series of measures to improve the PBM and PBA maturities, referring to the improvement priorities provided by the BATM assessment.

#### **5. Discussion**

BIM technology has been developed globally for a period of more than 20 years. Because BIM applications exist in different phases of the project life cycle, including design, construction, operation, and maintenance, and BIM applications involve many stakeholders, such as the designers, equipment supplies, construction companies, consulting-related enterprises, project owners, and even relevant government departments, the whole process of BIM applications is complex. As a result of the complexity of BIM applications, they are not as good as expected under many circumstances [57], although BIM has been well applied in some countries and some projects. To promote BIM applications, various BIM application maturity assessment models based on different enterprise perspectives and different project phases have been developed [17,22,42–52].

However, all of the BIM application maturity models have several obvious deficiencies. First, the assessment indexes of all models are different, and a unified assessment index system has not been derived. Second, these models also have huge discrepancies in the definition of maturity levels, with the number of maturity levels ranging from three to ten. Third, these models are built under specific business perspectives and specified project conditions, and have application limitations under other project situations. These deficiencies make it difficult for various BIM application maturity models to be popularized and applied. BIM application maturity models do not have the good effect expected by the public, and create difficulties for users in choosing these models [24]. Hence, a holistic model enabling BIM maturity assessments is necessary [17].

Considering the digital twin relationship between BIM applications and engineering projects, and that the purpose of BIM applications is to achieve the project objectives and BIM application processes are deeply integrated with project implementation processes, in this study, the eight performance domains and 37 desired outcomes of PMBOK 7th edition were selected as the assessment indexes of BATM. The selection of such indexes not only ensures that the BATM indexes are consistent with the processes and objectives of BIM applications and project management, but also avoids the dilemma of designing different assessment indexes for different purposes; thus, projects and organizations can then promote the improvement in BIM application maturity under the unified standard. At the same time, the assessment indexes based on PMBOK also indicate that BATM is applicable to all types of projects, whether they are building projects or highway projects. The selection of BATM assessment indexes is an innovation of this study. In addition, it should be noted that the BIM-related software, hardware, personnel, standards, and other indexes are not the assessment indexes of the project BIM application maturity, but are those of the organizational BIM capability maturity.

In the engineering industry, the main purpose of BIM applications is to serve the engineering projects. It is clear that the high level of BIM applications plays an assisting and supporting role in the project implementation, and the high level of project management creates higher requirements for BIM applications. In the context of the continuous development of digital technology, BIM applications and project implementations are increasingly embodied in a digital twin relationship. Through the comparison of the project management maturity in the real world and the BIM application maturity in the virtual world, it is easier to identify the inadequacies and problems in project management and BIM applications. Under the guidance of this idea, this study proposes the BATM model for BIM maturity assessment from the two dimensions of the virtual and real worlds. The two-dimensional maturity ideology of the virtual and real worlds is another innovation of this study.

With regard to the maturity level, this paper refers to a large number of documents and selects the five-level scheme, which has a more intuitive definition of the levels and is more commonly used [6,27,34–36,50]. The five levels of PBA maturity are the initial, repeatable but intuitive, defined process, managed and measurable, and optimized levels (the non-existent level occurs without PBA), and the five levels of PBM maturity are the initial, managed, defined, quantitatively managed, and optimizing levels. The five level schemes of the two dimensions are basically the same.

The application case of the BATM model shows that the model is simple and its effect is obvious. Based on the statistical analysis of expert scores and the radar graph of the two-dimensional maturity values, the deficiencies existing in the PBM and PBA can be visually and accurately identified. Furthermore, the priority improvement direction of BIM application can be determined immediately, and organizations and projects can advance along the BATM ladder.

In the case of multiple BATM assessments, the dynamic changes in two-dimensional maturity can be clearly observed, which will be more effective for the improvement in maturity.
