426
Ind. Eng. Chem. Res. 2005, 44, 426
ADDITIONS AND CORRECTIONS Volume 43, Number 10 Enhanced Continuous-Time Unit-Specific Event-Based Formulation for Short-Term Scheduling of Multipurpose Batch Processes: Resource Constraints and Mixed Storage Policies. Stacy L. Janak, Xiaoxia Lin, and Christodoulos A. Floudas* Page 2529. The schedule for example 4 with two extruders (case 2), shown in Figure 13, and the model and solution statistics for this case, shown in the fourth column of Table 5, correspond to a special case of the problem in which a constraint restricting the start of order 6 was imposed. If this special constraint is not included, the corresponding new optimal solution can then be found in Figure 13 and the associated model and statistics are shown in the last column of Table 5.
Figure 13. Schedule for modified example 4 with two extruders (case 2). Table 5. Model and Solution Statistics for Modified Example 4 four extruders three extruders two extruders simultaneously simultaneously simultaneously event points binary variables continuous variables constraints LP relaxation objective nodes CPU time (s)
4 150 513
12 458 2137
12 444 2137
1389 0 1.026 7 0.07
10 382 0 1.895 1374 6.53
10 382 0 7.334 38621 236.87
The authors thank Dr. Carlos Mendez for bringing to our attention their work (Mendez, C. A.; Cerda, J. A MILP framework for short-term scheduling of singlestage batch plants with limited discrete resources. Proceedings of the 12th European Symposium on Computer Aided Processing Engineering; Elsevier Science BV: Amsterdam, The Netherlands, 2002; pp 721-726). The solution shown above without the special constraint matches their reported solution. IE048866R 10.1021/ie048866r Published on Web 12/16/2004
