Regression testing is most often used in testing maintenance to existing programs.

回归测试最常用在已有测试的测试维护.

Though regression testing is costly, it is absolutely necessary in test process.

软件回归测试是代价较高的测试方法, 但是在软件测试过程中又是必不可少的.

To reduce the cost of regression testing, the test case prioritization method is proposed.

为了降低回归测试的测试成本, 提出了测试用例优先排序的方法.

Regression testing is conducted frequently on major, minor, and even bug-fix software or firmware releases .

回归测试经常执行在主要、次要以及甚至仅更正臭虫的软体或韧体的新版本发行。

To decrease the cost of maintaining the test suite and executing test cases in regression testing, test suite reduction techniques can be used.

在回归测试中为了减少维护测试用例集和执行测试用例的成本，可以采用测试用例集缩减的技术。

You just need to make refactoring a regular activity in whatever development process you are following and ensure that your changes are validated with appropriate regression testing.

无论你采取什么开发方式，你都需要将重构作为一种常规的活动，以保证你的更改是有效的。