由於激烈的競爭，研發團隊必須妥善管理內部和外部的網絡關係，以獲得廣泛且多元的資訊和資源並達成目標。雖然研發管理的研究學者曾指出，社會網絡對於專案績效的影響，但是並未將專案的發展階段納入考慮，也未就社會網絡關係的強弱與變化作深入地探討。因此，本研究針對四家科技公司的研發團隊為個案的研究，並進行跨個案的比較分析，以期瞭解專案經理人對於內外部的社會網絡的管理，是否會隨著專案階段的發展而呈現不同的變化。研究發現，在專案前期，研發團隊比較重視外部的連結與高層網絡之連結，以期蒐集專案所需的資訊及資源。到了專案中後期，反而比較專注在團隊內部網絡的結合以及爭取跨團隊網絡的支援，以完成專案的任務。

Due to furious competition, R＆D teams must manage their internal and external network relationships in order to search information and resources widely to achieve their goals. Researchers on R＆D management have pointed out the impacts of network relationships on project performance, however neither project stages have been taken into consideration nor the dynamics of network relationships have been explored deeply. Therefore, we conducted four case studies on R＆D teams across four different high-tech companies and used cross-case analyses to explore how project leaders manage social networks across the different project stages. Results revealed that in the early stages, R＆D teams focused more on both external social networks and upper manager's networks in order to search required information and resources. In the late stages, R＆D teams focused more on the collaboration of intra-team networks and the accessibility of cross-functional networks in order to perform well to the project mission.