We describe the design of an optimizer for 0-1 integer programming aimed at solving large problems. The algorithm is based on very simple operations giving it a low complexity, and we show that for large set covering problems it can produce very good solutions compared to other methods. This is the only optimizer in the Carmen system for airline crew scheduling, used by several major European a...

Scheduling problems are widely recognized as important optimization problems. Thus, scheduling theory has become a fundamental area within the general field of combinatorial optimization. Multiprocessor and shop scheduling problems are known to be hard to solve optimally. Scheduling problems are naturally very varied, both in application domains and in featured constraints. To date, researchers...

Many scheduling problems involve reasoning about tasks which may or may not actually occur, so called optional tasks. The state-ofthe-art approach to modelling and solving such problems makes use of interval variables which allow a start time of ⊥ indicating the task does not run. In this paper we show we can model interval variables in a lazy clause generation solver, and create explaining pro...

In real world scheduling applications, machines might not be available during certain time periods due to deterministic or stochastic causes. In this article, the machine scheduling with availability constraints for both deterministic and stochastic cases with different environments, constraints and performance measures will be discussed. The existing body of research work in the literature wil...

In this work we explore the use of deliberation scheduling for allocating computation among competing decision procedures in solving time-critical scheduling problems in stochastic domains. We present a two-level deliberation scheduling solution. At the higher level deliberation scheduling is used to partition innnite horizon scheduling problems temporally and sequence and allot computation tim...

Hydrothermal scheduling plays an important role in maintaining a high degree of economy and reliability in power system operational planning. The traditional scheduling methods have become inadequate to handle large scheduling problems and tend to be inefficient due to complex computational process. Efficient strategies have thus become an imminent necessity to solve the complex on-line schedul...

Most of the research literature concerning scheduling concentrates on the static problems, i.e problems where all input data is known and does not change over time. However, the real world scheduling problems are very seldom static. Events like machine breakdown or bottleneck in some situation impossible to predict. Dynamic scheduling is a research field, which take into consideration uncertain...

According to the coexistence of two production style: Single Small Serial Production and Batch Production in the current Enterprise, this article analyzed the scheduling problems of this production model and studied the working flow of this production scheduling problem. Using Genetic Algorithm for the Scheduling Hybrid Production, a new system for solving the problems of Scheduling Hybrid Prod...

We provide several non-approximability results for deterministic scheduling problems whose objective is to minimize the total job completion time. Unless P = NP, none of the problems under consideration can be approximated in polynomial time within arbitrarily good precision. Most of our results are derived by Max SNP hardness proofs. Among the investigated problems are: scheduling unrelated ma...