The phrase "a lengthy phase" is correct and usable in written English.
It can be used to describe a period of time that is extended or prolonged, often in the context of a process or development.
Example: "The project went through a lengthy phase of planning before any actual work could begin."
Alternatives: "an extended period" or "a prolonged stage".
Unlike CAFE standards, which only affect new cars from the major Detroit automakers like General Motors, Ford and Daimler-Chrysler, as well as imports like Toyota, Honda and Mitsubishi Motors, and only after a lengthy phase-in, a gas tax would apply to all drivers and would have an immediate effect.
The competition body said it would make an initial ruling by 23 March, by which time it should have decided whether to approve the transaction or submit it to a more lengthy "phase two" inquiry.
Software maintenance and evolution is an important and lengthy phase in the software life-cycle which can account for as much as two-thirds of the total software development costs.
Y's are likely to be bored and turned off by a project that begins with a lengthy training phase.
The Boston Marathon trial is expected to drag out through a lengthy sentencing phase, but Wednesday's opening statements follow a jury selection process which has taken several months.
For those, such as chancellor Philip Hammond, who would prefer to see a lengthy transition phase before Britain leaves the single market, this clause is a reminder that it could take more than a few days for the ink to dry on the goatskin parchment of the Queen's speech.
We had decided against this option because a lengthy feedback phase cannot be carried out feasibly with real-life objects.
Rice is a facultative short-day plant that flowers under long days (LD) after a lengthy vegetative phase.
Today's debut will be followed by a lengthy trial phase, and local regulators are also involved throughout in monitoring its progress.
OZ Minerals shipped its first loads of concentrate metal-bearing ore–from the mine last month, ending a lengthy development phase that saw concentrate metal-bearing 1 billiore fromalian dollars.
