5. Discussion
The theoretical and empirical findings show that the integration of the SRM process between the manufacturer and its first upstream tier of supplier within the case studies can take place through the integration of the SRM sub-processes. Nonetheless, firms must also tackle some obstacles to enable the SRM sub-processes integration within the studied cases. The summary of the analyses of research question 1 is as follows. The summary of the analyses of research question 2 is also as follows. In light of the information provided above, the manufacturer and its first upstream tier of supplier can integrate 11 sub-processes (1 sub-process is internal) within the studied cases in order to perform the SRM process with higher efficiency and effectiveness. The integration of strategic sub-processes between the partners can take place through major discussions and negotiations over the PSA. Partners should agree upon various themes such as the process improvement profit sharing and the metrics for the performance measurement, and clearly define the results of the agreement within the respective clause of the PSA in order to avoid further potential disputes. During the PSA negotiations, the integrated partners should have a team-orientation to enable the maximization of mutual benefits. The integration of the strategic sub-processes is rather informational because this integration requires exchange of significant quality of knowledge and information (Forslund & Jonsson, 2007)