## 4 The Second Workshop: Structure and Contents of the STEW Guide
### The Contents of the BIM Service Executing Guide (BEG)  
The BEG was set up to briefly guide the POs about two questions: how to develop a PO-centered BEP that is necessarily included in the OIRs/EIRs, and how to monitor a supplier's BEP throughout a BIM service contract. The BEP outlines the overall vision along with BIM implementation details for both the POs and suppliers to follow throughout a BIM contract. In this sense, the BEP should define the scope of BIM execution on the project, identify the process flow for BIM tasks, define the information exchanges between BIM stakeholders, specify the quality of deliverables from BIM implementation, and describe the required project and company infrastructure necessary for supporting the implementation [1].  
The BEP should be developed in the early stages of a project. In parallel with POs defining BIM scope, they need to develop their own BEP. In general, a four-step approach is followed by project owners when developing a BEP: identify the appropriate BIM goals and uses, design BIM execution processes and information exchange, define BIM deliverables, and identify the supporting infrastructure to successfully implement the BEP [21]. While this approach looks simple, it provides an adequate skeleton for developing a BEP.  
The BEP developed by the POs will be included in the OIRs/EIRs as a part of the RFP in a BIM tender process [20]. The OIRs/EIRs in general specify high-level BIM requirements for a project, while leaving project-specific requirements such as processes, individual responsibilities, and collaboration procedures to the supplier-proposed BEP. At the tender stage, prospective BIM suppliers will exploit their BEP for the proposed approach to satisfy the OIRs/EIRs. Once the contract has been awarded, the winning supplier then submits an advanced BEP to confirm the supply chain's capacities [34]. Since the BIM contract necessarily involves a BEP, it is beneficial for the POs to have the BEP templates that not only inform the potential BIM suppliers of the BIM expectations of the POs, but also lessen the time and effort required to fulfil the BEP requirements of each project [21].  
At the end of tender stage, as the project-specific BEP is established in collaboration between the PO and the supplier, the BEP will be included in the contract document so that communication procedures and collaboration processes among the architectural, electrical, mechanical, and civil BIM suppliers can be clear, thereby manifesting understanding of individual responsibility for BIM modeling, levels of development, and deliverables. The PO should require the supplier to review and coordinate the BEP with the entire BIM project team prior to submitting to them for final approval. The BEP needs to be considered as a living document that progresses throughout the project [1; 20; 21].  
Utilizing lists of exactly what information or deliverables are required by who at certain stages is very beneficial for both the POs and suppliers in communicating and collaborating with one another. Around the inception of most BIM projects, the POs are unlikely know enough to generate a full list of BIM modeling information and deliverables when they choose a supplier. This implies that the lists are likely to be developed over time with input from the right personnel at the right time.