phase in

To introduce, one stage at a time.

分阶段引介：一阶段一个地引入

phase out

To bring or come to an end, one stage at a time.

逐步撤除：一次一个阶段地结束

in (或 out of) phase

being or happening in (or out of) synchrony or harmony

（不）同相的（地）；（不）同步的（地）；（不）协调的（地）

the cabling work should be carried out &B{in phase with} the building work.

电缆工程应当与建筑工程同步进行。

in phase

In a correlated or synchronized way.

按阶段：用相关的或同步的方式

out of phase

In an unsynchronized or uncorrelated way.

不分阶段：用不同步的或不相关的方式