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

Table 9

Model 2a and Model 2b details.

Inc. rate (%)		Model 2a (IP)				Model 2b (CP)
		Obj.	Time (s)	No. of const.	No. of variab.	Obj.	Time (s); (fail lim.)	No. of const.	No. of variab.
15	365	Infeasible				No solution
20	376	Infeasible				No solution
21	382	Infeasible				No solution
22	386	37,056	877.23	677,214	876,709	37,056	7.07 (263.06)	264,586	122,992
23	386	37,056	886.41			37,056	7.09 (263.65)	264,586	122,992
24	390	37,440	898.57			37,440	6.16 (231.89)	267,066	124,224
25	390	37,440	906.35			37,440	6.29 (229.30)	267,066	124,224
30	409	39,264	915.33			39,264	6.75 (260.41)	278,846	130,076
46	456	43,776	928.12			43,776	8.09 (209.65)	307,986	144,552
47	462	Infeasible				No solution

The results in bold are proved to be optimal.
The increase rate (Inc. rate) corresponding to the lowest optimal value of the case.
No integer solution found.
Search terminated by limit, no solution found.