Both, depending on the situation and the context of the market. Companies in highly competitive spaces racing to beat each other to the next big breakthrough will put technology into production as soon as it is ready. Companies with the luxury of waiting to maximize profits and R&D will wait as long as they can.
There is a third option here, however: Technology can be both long-planned *and* spontaneous. It is entirely possible to have a very difficult problem you need to solve that you invest a great deal of R&D into. After a decade of work, you find the solution you've been searching for. In this case, a long, steady investment yielded the result that allows for quick deployment thereafter.
In other cases, the long, slow, grinding work simply yields a usable product. Both OLED and EUV technology are examples of projects that were trumpeted 10-15 years before being ready for commercial deployment. It took OLED TVs over a decade to get to market. Intel started talking about Extreme Ultraviolet Lithography back in 2002. They thought it'd be ready, IIRC, by 2004 - 2005.
EUV will actually be ready for manufacturing in 2020, 15-16 years after the research on it began.