;Water is an integral substance of life. However, due to serious changes of environment and climate, water resource is no longer abundant. Although the earth is mostly covered by water, the quantity of fresh water that human can use is less than 3%. What’s more, water resource is insufficient in many regions around the world. In Taiwan, because of the uneven distribution of rainfall in recent years led to many regions are facing the water restriction, and having severe impacts on people’s livelihood and business. Therefore, how to utilize water resources efficiently has become an important issue nowadays.
To deal with the water resource problem, many researchers have made a number of related researches, and developed the “Water Footprint” from the concept of “Virtual Water”. Water footprint can be seen as the comprehensive index for the product water use, and can also be the awareness of water resource management as well as the risk control for the business.
This study focuses on the color filter industry in Taiwan. TFT-LCD is the industry which requires water resources directly and indirectly. Color filter is the key component of the TFT-LCD, and shares the 20% of the entire cost. Thus, the purpose is to construct a mathematical model in respect of the blue water footprint and operation cost for the color filter supply chain, considering different combinations of raw materials from different suppliers, manufacturing processes, and transportation. In this study, we use single objective programming, and introduce the concept of environment cost, which is a way to convert the water footprint into monetary unit so that the model can optimize the supply chain cost and the water usage. In addition, this study also conducts the sensitive analysis of two scenarios, which are the changing of environment cost and total amount control of water footprint so that the company can have a better reference index, and utilize water resources more efficiently.