This study is to explore the transformation of the case company (called company A in this study) in the power supply industry from an OEM factory of its U.S. based mother company into a technical production and marketing company, and the way of overcoming the bottleneck of sales performance under coopetition with other Taiwan competitors or planning a more appropriate strategy in such a value net, so as to rapidly build up distribution channel, gain competitive advantage and enlarge market share. This study adopts a case study method to achieve the following objectives through secondary data collection and in-depth interview: (1) understand the upstream/downstream relation of company A in the power supply’s industrial value chain; (2) explore the problems confronted in the coopetition after Company A’s positioning and current conditions are clearly known; (3) propose solutions and strategies for the problems confronted by company A’s products, and design company A’s product strategy and help it to obtain the competitive advantage in the coopetition. This study also uses corporative value chain, SWOT analysis, and STP analysis techniques to find the current advantages and disadvantages and the positioning of company A according to eight product strategies: product positioning strategy, product repositioning strategy, product overlapping strategy, product category strategy, product design strategy, product phase-out strategy, new product strategy, and diversification strategy. Then, this study formulates the product mixed strategies and take corresponding actions, when the company A’s situations are understood. A conclusion on the appropriate combination of product strategies for A company is drawn as follows: new use and repositioning of product repositioning strategy, proprietary brands of product overlapping strategy, single brand of product category strategy, and customized products and standardized products of product design strategy (revisable), and product improvement/correction and product imitation of new product strategy.