| Article ID: | iaor20023217 | 
| Country: | Netherlands | 
| Volume: | 139 | 
| Issue: | 2 | 
| Start Page Number: | 293 | 
| End Page Number: | 301 | 
| Publication Date: | Jun 2002 | 
| Journal: | European Journal of Operational Research | 
| Authors: | Tadei Roberto, Croce F. Della, Ghirardi M. | 
| Keywords: | programming: branch and bound | 
We consider the two machine total completion time flow shop scheduling problem. This problem is known to be NP-Hard in the strong sense. An improved Lagrangean relaxation approach is proposed. Two new dominance criteria are introduced to curtail the enumeration tree. A branch-and-bound algorithm capable of solving to optimality medium size problem instances is presented.