## 5 Discussion and Conclusions  
This paper presents the current status of the external stone cladding system in the production and installation stages in Hong Kong. The results from the case studies, questionnaire survey, and interviews offer valuable insights regarding the system at the two stages. First, around 40% of respondents believed that the current control mechanism is insufficient compared with other external facade systems (in Figure 4). Second, the stone suppliers and factories mostly from Mainland China (in Figure 5) vary significantly in their scale and quality. The quality management, supervision by TCPs, quality assurance scheme by the manufacturer, and initial test should be considered to enhance the quality control at the production stages (in Figure 7). Third, close supervision and periodic inspection during production and delivery are essential for successful installation stage of the system (in Figure 8). Lastly, the varied perspectives depending on their workgroup are confirmed. For the statement on the inadequacy of the present statutory control mechanism, the design team expressed their degree of agreement much stronger than the construction team (in Table 2). Furthermore, the design team rated the factor' material and technical specifications' significantly higher (U = 155, \(p\) = 0.004), while 'protection for the delivery of stone panel' much lower than that of the construction team. The lack of mutual understandings between workgroups was considered as one of the most detrimental factors against the supply chain management implementation in Hong Kong ([PERSON] et al., 2004). Therefore, it is worth studying the differences in detail among the workgroups of the external stone cladding system in future research. Based on the results and findings of this study, the possible measures to improve and enhance the quality and performance of the external stone cladding system are recommended as follows:  
1. Pre-testing of stone materials and anchorage system should be performed to ensure the required standards specified in the contract and legislation in the production stage. 2. Quality assurance should be executed in the supply chain and production process so that its end products can consistently meet the specified quality and performance standards. 3. Regular inspections and audits in the production stage are highly recommended. Besides, having technically competent persons of the consultant team and contractors is suggested to perform this task and record the findings in logbooks. 4. Continuous quality supervision should be conducted on-site, and a comprehensive checklist should be devised for control and monitoring on quality of works during the installation stage. Despite the fact that this study conducted the systemized research methods, the research scope and objectivity might be limited. The number of variables, case projects, and interviewees may be insufficient to reflect an overall view of the situation in Hong Kong. Other variables, such as types of clients [19; 20], stone types [2; 21], and project characteristics [20; 22], may have substantial effects on the quality performance in the construction industry. In line with this study, further studies complementing