### 3.7.220. Sequencing with release times and deadlines

Denotes that, by reduction to sequencing with release times and deadlines, deciding whether a constraint has a solution or not was shown to be NP-hard. The sequencing with release times and deadlines problem can be described as follows: given a set of non-overlapping tasks and, for each task a length, a release time and a deadline the question is to find a schedule that satisfies all release time constraints and meets all the deadlines.