Phase in means introduce something gradually, in stages: the school will phase in the new timetable over two terms. The new thing appears in one department first, then in the rest, and for a while old and new work side by side. People phase in rules, systems and equipment. The opposite is phase out: remove gradually.
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phase in a system; phase something in over a period; phase it in
- The school will phase in the new timetable over two terms.
- We are phasing the equipment in one department at a time.
- The revised rules were phased in gradually.
What changed
First versionThe system is new, so we will phase in it gradually.
RevisionThe system is new, so we will phase it in gradually.
Most verbs take the object right after them, so phase in it looks logical. But with a phrasal verb, a pronoun goes between the parts: phase it in. With a noun both orders work: phase in the system or phase the system in.
Introduce means bring in, with no stages: the school introduced a new timetable. Phase in means bring in step by step: the school is phasing in a new timetable. Postpone means move to later: the launch is delayed, but when it happens, it may happen all at once.
Your turn
Choose the particle for introducing a system gradually: The company will phase ___ the new process over six months.
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in — Introducing something gradually is phase in. Phase out would mean gradually getting rid of the process.
Describe how something new was gradually introduced at your work, school or in your city.
The library will phase in self-service borrowing, starting with the main branch.
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