A schedule is produced and published each week by the superintendent, project manager and/or general contractor that outlines what is occurring in the next 2 or 3 week period of smaller actionable tasks to be done in that 2 or 3 week timeframe. The selection of what kind of lookahead timeframe you should use is really based on an evaluation of what works best for your kind of project and in some circumstances the timeframes used could even be longer.
This lookahead planning is done independently of the main project schedule.
The output of lookahead planning, resulting from exploding master schedule activities by means of the activity definition model, screening the resultant tasks before allowing entry into the lookahead window or advancement within the window, and execution of actions needed to make tasks ready for assignment when scheduled. Lookahead schedules may be presented in list form or bar charts. (LeanConstruction Glossary L)