Their defense markets are too small to sustain economically viable production runs.

他们的国防市场太小，就经济可行性而言不足以维持生产。

柯林斯例句

The factory is no longer economically viable.

这个工厂在经济上已经维持不下去了。

《牛津高阶英汉双解词典》

It is only their investment that makes the programme economically viable.

因为他们的投资,这个项目在经济上才得以通过.

《简明英汉词典》