## 4 In-Depth Analysis and Results
### Findings and Implications
#### 4.2.2 Devising a New Conceptual Model  
Given the results of the integrative literature review, we take both the lack of a complete conceptual model that is accepted by the scientific and practitioner community and the shortcomings mentioned above as an opportunity to propose a new conceptual model for BIM-LPS integration.  
This new conceptual model aims to account for the BIM-LPS interactions presented in Table 1 and the above-mentioned needs of adding new functionalities. These new functionalities are:  
* Establishing clear roles (e.g., similar to the Scrum framework)
* Deploying on (digital) Kanban boards Enhancing visualization, emphasizing LPS' pull-system characteristics, adhering to digitization [97; 98; 99]  
This addition is intended to give the model on a conceptual level the properties that make it possible to derive holistic, IT-oriented production management systems based on BIM and LPS. These could become the source of new information systems. For this purpose, the proposed model also highlights a software-neutral information flow from BIM to the LPS process steps and vice versa.  
In order to establish a connection to existing theory, and thus meeting the requirements of the DSR approach, our model (Figure 9) is based on the original LPS model by [PERSON] [36]. Our model refers to the definition of [PERSON] and [PERSON] [100], who stated that a conceptual model comprises an \"external representation created by researchers, teachers, engineers, etc., that facilitates the comprehension or the teaching of systems or states of affairs in the world\".  
On the one hand, this original model is extended by the BIM part which serves both as input and output/visualization instrument. On the other hand, a (digital) Kanban system should help to balance load to capacity [36], to optimize flow through limited Work-in-Progress (WIP) [101], and to improve visual management [98; 102]. What is more, Kanban, being a system to provide information as pull signals along value-adding-chains, applied to the LPS, it could help to release new work, when tasks are completed as demanded by [PERSON] [103].  
Lastly, we introduce new roles for enhanced process compliance and customer satisfaction in the style of Scrum. We need a role (\"new role 1\") that precisely implements the LPS methodology in  
Figure 9: Conceptual model for BIM-LPS integration.  
conjunction with BIM to prevent partial implementations as we have seen in pure LPS implementations. Besides that, we want to introduce another role (\"new role 2\") that ensures that process planning and construction execution according to this model is in line with the customer requirements. Of course, both roles could also be filled by the same person, for example, the site manager in a general contractor environment or an external project manager.  
As a consequence, using LPS terminology, the new role 2 is responsible for aligning what SHOULD be done to what WILL be and to what was done (DID) from the customer perspective. The new role 1 has been introduced to define a person who moderates the combined BIM-Last Planner(r) process according to this conceptual model. The BIM model serves as an information input source for the planning process according to the LPS and for status visualization. The latter can also be visualized by means of a digital Kanban system. Furthermore, the Kanban system can be capitalized for defining what CAN be done when load is visually balanced to capacity (will). Comprising a circular process, this model can be interpreted as being embedded in the plan-do-check-act (PDCA) cycle by [PERSON] [104].