This paper considers a bi-objective scheduling problem in a flexible manufacturing cell (FMC) which minimizes the maximum completion time (i.e., makespan) and maximum tardiness simultaneously. A new mathematical model is considered to reflect all aspect of the manufacturing cell. This type of scheduling problem is known to be NP-hard. To cope with the complexity of such a hard problem, a genet...

Given a system model where machines have distinct speeds and power ratings but are otherwise compatible, we consider various problems of scheduling under resource constraints on the system which place the restriction that not all machines can be run at once. These can be power, energy, or makespan constraints on the system. Given such constraints, there are problems with divisible as well as no...

In 1978, Schaefer [12] considered a subclass of languages in NP and proved a “dichotomy theorem” for this class. The subclass considered were problems expressible as “constraint satisfaction problems”, and the “dichotomy theorem” showed that every language in this class is either in P, or is NP-hard. This result is in sharp contrast to a result of Ladner [9], which shows that such a dichotomy d...