An Integrated Approach for Shift Scheduling and Rostering Problems with Break Times for Inbound Call Centers

Table 2

Syntax definitions used in OPL expressions and constraints.

Syntax	Definition
	Integer expression to access the length of an interval.
	Constraint used to prevent intervals in a sequence from overlapping.
	Constraint used to enforce the presence of intervals.
	Constraint used to synchronize the start and end of intervals.
	Keyword for stepwise linear functions.