Now, anybody who's ever GMed a game knows that if one thing is guaranteed to happen it's that the players will do something you haven't planned for. Railroading them back into a set of scripted events is just going to discourage their creativity and take something away from the gaming experience. I don't play that way, and neither does anybody I know.
So as a general rule scripted adventures are a bad idea for role playing games. However, there is situation where using scripted adventures is entirely appropriate: linked wargaming scenarios.
Have at you!
In this case the script would cover the narrative events linking the various scenarios, while the outcome of the battles would determine the course the script would take. Think of it like a video game. You punch some buttons to fight some opponents, then you sit back and watch a cut-scene that advances the story and takes you to the next fight where you punch some more buttons. Same thing, only you roll dice and don't use as much electricity.
Say your prayers, pardner!
Ideally you would organize the script and scenarios in a flowchart, so that the events of any given fight determine which chain of events follow. For example, space pirate Capt. Scorpio raids a landing field warehouse where he knows a smash-bot to be stored. If the pirates win the scenario, they'll be able to field the smash-bot in the next encounter; if not, they not only won't have a shiny new robot, they may have the space rangers hot on their heels. In either case, the outcome of the fight decides which way events will go within the general confines of the story.
Stop contradicting me, Duchesse.
So maybe it's time to dust off those old scripted Star Wars adventures and use them for a little inspiration.
[pics via Negromundheim and The Old Gamers’ Den]