. . . [E]very single writer I met likened writing for....

“ . . . [E]very single writer I met likened writing for television to one thing--laying track for an incoming speeding train. The story is the track and you gotta keep laying it down because of the train. That train is production. You keep writing, you keep laying track down, no matter what, because the train of production is coming toward you--no matter what. Every eight days, the crew needs to being to prepare a new episode--find locations, build sets, design costumes, find props, plan shots. And every eight days after that, the crew needs to film a new episode. Every eight days. Eight days to prep. Eight days to shoot. Eight days, eight days, eight days, eight days. Which means every eight days, that crew needs a brand-new script. And my job is to damn well provide them with one. Every. Eight. Days. That train of production is a'coming. Every eight days that crew on that soundstage better have something to shoot. Because the worst thing you can do is halt or derail production and cost the studio hundreds of thousands of dollars while everyone waits. That is how you go from being a TV writer to being a failed TV writer. ”

Shonda Rhimes

From : Year of Yes: How to Dance It Out