由於每一艘船舶於一定期間內所能創造出之貨櫃載運數(可視為一艘船之貨載容量)，將隨著其所配置之航線特性、泊靠港口之多寡、航次週期等因素而有所差異。顯然的，若採單艘船舶之設計滿載容量為基準，來衡量船隊於一定期間內之貨載容量，將是不合理的。本研究跳脫傳統最適船型之方法，而採以航商整體船隊之觀點，來探討臺灣四大貨櫃航商之最適產出量，並進而窺知其船隊容量使用率之情形。本研究發現：短期上，所有航商幾乎皆面臨超額容量現象。而承受整體國際貨櫃市場船隊擴充之競爭壓力，應是造成臺灣四大貨櫃航商其船隊艙位投入過多之主因。再者，無論在船型大小與船隊數量皆具經營優勢之遠洋航商，其船隊容量之運用效率並不一定比近洋航線業者佳。所以大型船舶與大量船隊，其並不能保證一定具有經營效率之優勢。

Due to the variations on the port selection and sailing frequency decision for a given containership during a time period, the optimal containership size for different carriers is still an undetermined and unrealistic issue even though the technically designed full capacity for a given containership is available. Instead of the traditional approach by focusing on a given sailing route, this study has utilized the concept of capacity output to investigate the efficiency of container fleet for the four major container carriers in Taiwan. This paper has found that the four carriers all have faced a severe overcapacity situation in the short run. The reason that enforces the four carriers to inefficiently expand their fleet capacity is the fact that the major carriers in the international container transportation market have competitively introduced the larger and the more containership into market in the past decade. Meanwhile, this paper has also shown that the tendency towards enlarging the containership size and employing more ships is not a necessary condition for the four carriers to create the cost advantage of their fleet operation.